There is not a built in server behavior or property for this but it could be done with some custom coding. The idea is that you can do a check to see if there are any values for a particular column, if not then do not print the column or anything in it. This would be implemented with some if statements around the table header and column <td>'s in the cart display page.
There are a lot of internal eCart values and functions that you can make use of, you can check them out in the <cartname>_php.php file in the WA_eCart folder. You will need a way to check on each of these cart columns and if any items have values for these columns you should display that column.
