Help:Introduction to tables with Wiki Markup/2
Introduction to tables
How and why
Editing tables
The basics
Expanding tables
Adding rows and columns
Summary
Review of what you've learned
When you use the 
toolbar button to insert a table, it actually inserts markup text into the article for you to edit. There are two common ways to lay out this markup that you amy see around Wikipedia:
Data is arranged like a table
This is useful when there aren't too many columns and the cell contents are short (e.g. just numbers). This is the markup layout that the 
button will create.
{| class="wikitable"
|+ Caption
|-
! Header C1 !! Header C2 !! Header C3
|-
| R1C1 || R1C2 || R1C3
|-
| R2C1 || R2C2 || R2C3
|}
Cells are arranged vertically
With lots of columns, or cells with long contents, putting each cell on a new line can improve readability of the markup.
{| class="wikitable"
|+ Caption
|-
! Header C1
! Header C2
! Header C3
|-
| R1C1
| R1C2
| R1C3
|-
| R2C1
| R2C2
| R2C3
|}
Both of which look like:
| Header C1 | Header C2 | Header C3 |
|---|---|---|
| R1C1 | R1C2 | R1C3 |
| R2C1 | R2C2 | R2C3 |
All you have to do is place this where you want it in the article, edit it to contain the information you're trying to display, and hit save.
