| head col1 | head col2 | head col3 |
|---|
| row1 col1 | row1 col2 | row1 col3 |
| row2 col1 | row2 col2 | row2 col3 |
Use the table bbcode (button on the right of the editor), and inside it you can specify the content in this format:
[code]
head col1|head col2|head col3
row1 col1|row1 col2|row1 col3
row2 col1|row2 col2|row2 col3
[/code]