The below example uses a gap of 10. You can also individually colour tables or rows. Here's the tag for that last table, just the table tag mind. That's just the enclosing tag, then you have to define the data itself. There are two items to a table.
Table rows and table data.
The row tag encloses one or more table data tags. Now, this is where it gets confusing, because one of those table data tags could span for more than one cell. For example, the purple cell on this page spans all of the rows down to the bottom of the page. The first TD tag contains nothing, the second contains the heading, and the third contains nothing. Then there's another TR tag, and 3 more TD tags.