HTML tables are not illegal
While the current push for web standards and tableless, CSS-based layout is great for the web, I have seen some confusion surrounding the use of tables. It’s important to remember that tables are still perfectly fine to use. Do your best to avoid using tables for layout, but if what you are marking up is tabular data, tables are what you should use.
Advanced Tables Tutorial explains how to use tables for tabular data. Tables can get quite a bit more complex than this tutorial shows, and there are some attributes available that aren’t mentioned, but it’s a great start.
In Tackling Tables, Andy Arikawa shows how CSS can be used to make a data table look good.