The custom HTML widget is a powerful widget as it allows you to embed any kind of custom code.
When you drag the widget to where you want it to be on your site, a pop-up will appear allowing you add any custom code. This could be some HTML to build a table using the well-known table tags, or some embed code for a game from an online games site, or any other code that you might want to add!
Please be careful though, badly formed code can affect your site's performance, or in the worst case, break the layout. If you are having troubles embedding code correctly, please email firstname.lastname@example.org and we'll help you out!