Shopping Form & Cart Page Table Formatting

Hey there :)

I can't seem to figure out where/how to change the table width on the shopping form and cart pages. The views seem to be setting the tables at various widths (i.e. 4 columns and 6 columns), and nothing in the view settings or the page region settings seems to be able to change these width settings. 

I'd like the tables to span the entire width of the page (12 columns), and to know how to make this happen.