I had a look at your source code and have an idea which may work.
Try this:
Get rid of the margins in the table then wrap the table in a <div> tag with the width of the image you're trying to align it with like this:
<div style="width: 900px; margin-left:auto; margin-right:auto;"><table id="web-buttons-idld2xa">REST OF MENU BUTTON CODE</table></div>
All you'll need to do is replace the 900px
with whatever the width of the section you want to align it with is.