obviously CSS is better than tables, but try using
<table style="margin: auto; text-align: left;">
(as in, add the style section into your table tag)
Then put a div around the entire page with text-align: center;
<div style="text-align: center;">
your table and page contents
On the other hand, if you aren't concerned at all about accessibility and just posted in the wrong forum, nest a table round the lot and centrally align the table inside it. Nested tables are a bad idea though...