You can code a webpage layout without tables! Tables aren't meant to be used for layouts, I used to use them when I didn't know about CSS and divs. Tables are to be used for data (tabulated obviously) and you can use CSS and divs to construct a layout for the page, it may take some more work but it's more accessible and generally a better practice
you will also have take into consideration that, when using CSS not all browsers will display correctly, you might have to resort to CSS hacks or even javascript to make your code compatible across browsers.
Indeed, not all browsers are CSS compliant, for example my site which I'm working on currently displays differently in Firefox, Opera, Safari and IE - meaning I need to work on the CSS to make it display correctly in all of the browsers (an easier way would be to use JS or PHP to find the browser type and include a working stylesheet for that specific browser...)
