We support Markdown pretty much everywhere on CodePen. We just tweaked it a little bit to now allow tables everywhere. You could always do HTML tables, but Markdown tables are a little quicker to write out. They look like this:

|     | this  | little  | piggy |
|-----|-------|---------|------:|
| one | alpha | hello   | 0.001 |
| two | beta  | goodbye | 0.002 |

The right row is right-aligned. It's pretty easy to memorize, but there is a great generator tool if you forget.

Used a Pen description, you'll get simple styles like this:

Feel free to use them in comments or on your blog as well.