They decorate the cake tables. If you want to personalize the look of the cake table they most likely will, if you drop off the items at Franks in advance.
They decorated ours with linens and fake flowers that matched our wedding colors and DH and I made our own flower bouquet in a vase that we added to the table. The cake stand, provided by Disney, was perfect too!
Edited to add: at WL there is a separate "side board" table and that is where they had all of the beverages, champagne and cider in a bucket and water pitchers, and all of the glasses. We put our guest book on the side board too, which was also covered in matching linens. They did a beautiful job!