Oh - ok...being able to see the css sheet makes me understand. I do know about that aspect of CSS. For some reason I thought he was talking about something entirely different.
The problem I have with using CSS to place content in that manner is that, at least when I tried it (and I'm obviously no expert), if I placed any statically-sized content that was just as wide or wider than the dimmensions defined in the CSS sheet, or if you re-size the browser so it was no longer as wide as defined in the stylesheet, it would do weird things to the 'tabled' look - ie, the image 'floats' across other content, obscuring, say, side menus or whatever. I still see that happen on other sites, particuarly blog sites - don't like it; can't stand it. Even in, say, the Cannon RAW browser, I hate that floating color/WB adjustment etc. menu because it can put the image behind the menu, and use the 'stacked/attached' menu option instead.
I never delved too deeply into trying to figure a way around the problem in terms of webpages - perhaps there is one/I assume there is one.