Table height

Does anyone know why there is no HEIGHT attribute for a table?  You can specify the width, so why not the height?  I'm trying to find a way to make a table that goes to the bottom of the users screen.  In particular, there are going to be 3 vertical columns that have different background colors and span the entire lenth of the page.  I can't seema to get it to work, and I can't find any "valid" attributes or methods to accomplish this.  Any help would be appreciated.
Thanks,
Pete