Nope.
It helps if you know a little bit about how CSS works, because the Pyjamas User-Interface widgets, like all Widget Sets, are designed around "function" and "purpose", not "form" or "look". It would also help if you had a basic grasp of a tiny bit of HTML, such as what <b> etc. does. For everything else, such as tables, there are Widgets such as Grid that are much more practical to use.