If you're using the webpart scroll all the way to the bottom of the properties and enable the output filter checkbox then in the last dropdown convert all table tags to div and they will be rendered as div tags with classes assigned to them.
If you're using the widget then you have to,make a change at the widget level to show that system property and enable the visibility on those properties for the widget.
If you don't want to convert the table layout to a div layout then you can use jQuery to turn those categories into a tablet out. The categories will render a class on them if you use the auto layout. Or you can create your own custom layout,