Preprocess a views template
In general, every .tpl.php file has an equivalent preprocess function for it.  And, in general, the preprocess function and template files have the same name (in the Drupal sense).

The function you want is template_preprocess_views_view_table().  You can place this in a module, or in your theme.  Just name it accordingly.

Look at the default preprocess function for how the $view gets pulled out and/or dpm($variables['view']).  You will likely need to examine it to limit the function to just the view/display you need.     

You can also try implementing MYMODULE_preprocess_views_view_table__commerce_cart_form() to limit to just that instantiation, but I don't recall if the Views module will do this.

The Theme Developer module can also help out tracking down what preprocess functions get called for each .tpl.php file.