That would work well, but if you do that, you no longer are enjoying pizza in the tub, instead you are eating a burrito in the bathtub, and we all know that isn't going to end well.
I enjoy reading a book in the bathtub while eating a pizza, so I am going to enjoy celebrating today. I have a floating pizza pan, and best of all, you don't need napkins as you can just wash off any spillage from the pizza. The book pages can get soggy if you are not careful while reading, so remember to get a grip folks.