Quickly format tables in ASCII. Great for code comments, or Github Markdown!
Play with it: https://ozh.github.io/ascii-tables/
Col1	Col2	Col3	Numeric Column
Value 1	Value 2	123	10.0
Separate	cols    with a tab or 4 spaces	-2,027.1
This is a row with only one cell
Press Create Table to get something like:
+----------------------------------+---------+------------------------+----------------+
|               Col1               |  Col2   |          Col3          | Numeric Column |
+----------------------------------+---------+------------------------+----------------+
| Value 1                          | Value 2 | 123                    |           10.0 |
| Separate                         | cols    | with a tab or 4 spaces |       -2,027.1 |
| This is a row with only one cell |         |                        |                |
+----------------------------------+---------+------------------------+----------------+
+==================================+=========+========================+================+
|               Col1               |  Col2   |          Col3          | Numeric Column |
+==================================+=========+========================+================+
| Value 1                          | Value 2 | 123                    |           10.0 |
+----------------------------------+---------+------------------------+----------------+
| Separate                         | cols    | with a tab or 4 spaces |       -2,027.1 |
+----------------------------------+---------+------------------------+----------------+
| This is a row with only one cell |         |                        |                |
+----------------------------------+---------+------------------------+----------------+
                Col1                  Col2              Col3            Numeric Column  
 ---------------------------------- --------- ------------------------ ---------------- 
  Value 1                            Value 2   123                                10.0  
  Separate                           cols      with a tab or 4 spaces         -2,027.1  
  This is a row with only one cell                                                      
|               Col1               |  Col2   |          Col3          | Numeric Column |
|----------------------------------|---------|------------------------|----------------|
| Value 1                          | Value 2 | 123                    |           10.0 |
| Separate                         | cols    | with a tab or 4 spaces |       -2,027.1 |
| This is a row with only one cell |         |                        |                |
               Col1               |  Col2   |          Col3          | Numeric Column 
----------------------------------|---------|------------------------|----------------
 Value 1                          | Value 2 | 123                    |           10.0 
 Separate                         | cols    | with a tab or 4 spaces |       -2,027.1 
 This is a row with only one cell |         |                        |                
ASCII table (reStructuredText Grid style)
+----------------------------------+---------+------------------------+----------------+
|               Col1               |  Col2   |          Col3          | Numeric Column |
+==================================+=========+========================+================+
| Value 1                          | Value 2 | 123                    |           10.0 |
| Separate                         | cols    | with a tab or 4 spaces |       -2,027.1 |
| This is a row with only one cell |         |                        |                |
+----------------------------------+---------+------------------------+----------------+
ASCII table (reStructuredText Simple style)
 ================================== ========= ======================== ================ 
                Col1                  Col2              Col3            Numeric Column  
 ================================== ========= ======================== ================ 
  Value 1                            Value 2   123                                10.0  
  Separate                           cols      with a tab or 4 spaces         -2,027.1  
  This is a row with only one cell                                                      
 ================================== ========= ======================== ================ 
|| Col1                             || Col2    || Col3                   || Numeric Column ||
|  Value 1                          |  Value 2 |  123                    |  10.0           | 
|  Separate                         |  cols    |  with a tab or 4 spaces |  -2,027.1       | 
|  This is a row with only one cell |          |                         |                 | 
.----------------------------------.---------.------------------------.----------------.
|               Col1               |  Col2   |          Col3          | Numeric Column |
:----------------------------------+---------+------------------------+----------------:
| Value 1                          | Value 2 | 123                    |           10.0 |
:----------------------------------+---------+------------------------+----------------:
| Separate                         | cols    | with a tab or 4 spaces |       -2,027.1 |
:----------------------------------+---------+------------------------+----------------:
| This is a row with only one cell |         |                        |                |
'----------------------------------'---------'------------------------'----------------'
 o88888888888888888888888888888888888(_)888888888(_)888888888888888888888888(_)88888888888888888o 
(_)               Col1               (_)  Col2   (_)          Col3          (_) Numeric Column (_)
(888888888888888888888888888888888888(_)888888888(_)888888888888888888888888(_)888888888888888888)
(_) Value 1                          (_) Value 2 (_) 123                    (_)           10.0 (_)
(_) Separate                         (_) cols    (_) with a tab or 4 spaces (_)       -2,027.1 (_)
(_) This is a row with only one cell (_)         (_)                        (_)                (_)
 O8oooooooooooooooooooooooooooooooooo(_)ooooooooo(_)oooooooooooooooooooooooo(_)oooooooooooooooo8O 
//==================================[]=========[]========================[]================\\
||               Col1               ||  Col2   ||          Col3          || Numeric Column ||
|]==================================[]=========[]========================[]================[|
|| Value 1                          || Value 2 || 123                    ||           10.0 ||
|| Separate                         || cols    || with a tab or 4 spaces ||       -2,027.1 ||
|| This is a row with only one cell ||         ||                        ||                ||
\\==================================[]=========[]========================[]================//
........................................................................................
:               Col1               :  Col2   :          Col3          : Numeric Column :
:..................................:.........:........................:................:
: Value 1                          : Value 2 : 123                    :           10.0 :
: Separate                         : cols    : with a tab or 4 spaces :       -2,027.1 :
: This is a row with only one cell :         :                        :                :
:..................................:.........:........................:................:
╔══════════════════════════════════╦═════════╦════════════════════════╦════════════════╗
║               Col1               ║  Col2   ║          Col3          ║ Numeric Column ║
╠══════════════════════════════════╬═════════╬════════════════════════╬════════════════╣
║ Value 1                          ║ Value 2 ║ 123                    ║           10.0 ║
║ Separate                         ║ cols    ║ with a tab or 4 spaces ║       -2,027.1 ║
║ This is a row with only one cell ║         ║                        ║                ║
╚══════════════════════════════════╩═════════╩════════════════════════╩════════════════╝
┌──────────────────────────────────┬─────────┬────────────────────────┬────────────────┐
│               Col1               │  Col2   │          Col3          │ Numeric Column │
├──────────────────────────────────┼─────────┼────────────────────────┼────────────────┤
│ Value 1                          │ Value 2 │ 123                    │           10.0 │
│ Separate                         │ cols    │ with a tab or 4 spaces │       -2,027.1 │
│ This is a row with only one cell │         │                        │                │
└──────────────────────────────────┴─────────┴────────────────────────┴────────────────┘
|               Col1               |  Col2   |          Col3          | Numeric Column |
|----------------------------------|---------|------------------------|----------------|
| Value 1                          | Value 2 | 123                    |           10.0 |
| Separate                         | cols    | with a tab or 4 spaces |       -2,027.1 |
| This is a row with only one cell |         |                        |                |
||             Col1               ||  Col2  ||          Col3         || Numeric Column ||
| Value 1                          | Value 2 | 123                    |           10.0 |
| Separate                         | cols    | with a tab or 4 spaces |       -2,027.1 |
| This is a row with only one cell |         |                        |                |
{| class="wikitable"
! Col1
! Col2
! Col3
! Numeric Column
|-
| Value 1
| Value 2
| 123
| 10.0
|-
| Separate
| cols
| with a tab or 4 spaces
| -2,027.1
|-
| This is a row with only one cell
|
|
|
|}
Leading characters can be added by selecting a comment style:
| Style | Characters | Usage | 
|---|---|---|
| none | "" | no comment style applied | 
| doubleslant | "// " | C++/C#/F#/Java/JavaScript/Rust/Swift | 
| hash | "# " | Perl/PowerShell/Python/R/Ruby | 
| doubledash | "-- " | ada/AppleScript/Haskell/Lua/SQL | 
| percent | "% " | MATLAB | 
| singlespace | " " (1 space) | MediaWiki | 
| quadspace | " " (4 spaces) | |
| singlequote | "' " (single quote) | VBA | 
| rem | "REM " | BASIC/DOS batch file | 
| c | "C " | Fortran IV | 
| exclamation | "! " | Fortran 90 | 
| slantsplat | "/* ... */ " | CSS | 
| xml | "<!-- ... -->" | XML | 
WTFPL. Do whatever the hell you want with it.