CSS way to horizontally align table

Steven is right, in theory:

the “correct” way to center a table using CSS. Conforming browsers ought to center tables if the left and right margins are equal. The simplest way to accomplish this is to set the left and right margins to “auto.” Thus, one might write in a style sheet:

table
{ 
    margin-left: auto;
    margin-right: auto;
}

But the article mentioned in the beginning of this answer gives you all the other way to center a table.

An elegant css cross-browser solution:
This works in both MSIE 6 (Quirks and Standards), Mozilla, Opera and even Netscape 4.x without setting any explicit widths:

div.centered 
{
    text-align: center;
}

div.centered table 
{
    margin: 0 auto; 
    text-align: left;
}


<div class="centered">
    <table>
    …
    </table>
</div>