More or less what Russell is saying and:
You can have a hierarchy of tab pages and a hierarchy of tab controls. Generic layer for standard properties etc and specific with the appropriate tab pages and nvo's scoped for tab pages. Finally that is placed on one or more windows with no need to add tab pages there. (If you really want to do that, there is always the olde OpenTab() )
So: Yes you can't, but perhaps you wouldn't really want to.