You can use any HTML code when you're working with PHP. PHP is a server processing language, it is seperate from the actual HTML code of the page, which allows you to use any HTML you want, tables or CSS divs.
Can use anything you like. Tables are common for tabular data like, I don't know, the results from a database maybe.
PHP actually stands for Hypertext Preprocessor (which is odd, but let's leave it at that) so one of its core functionality is process HTML
PHP stands for (to be frustrating): PHP: Hypertext Preprocessor It's a recursive acryonym (think that's what its called, I'll be picked out on it no doubt if it isn't.)
You can choose yourselve, if you like divs you use divs if you like tables you use tables. As writen above; CSS is not ment for tabulair data (wich tables are ment for)
Actually to make it clear: PHP - generates HTML that is later displayed. So with it you can create tables or divs and then ready HTML is displayed on the browser. hope that explains...