That could be one way of approaching it, although I'm not 100% sure that tables printed within a book, on pages that are not sold separately and are not necessarily readily visible to a consumer wanting to purchase the book from a vendor, amount to trade dress. If they are trade dress, then use of them would be OGL-violating. If they are not trade dress but are the subject of copyright, then use of them would also be OGL-violating, as the user wouldn't have the rights in respect of them that the OGL requires him/her to have.
In the GSL WotC covers all its bases, characterising the licensed templates and tables as falling within WotC's property rights pursuant to and and all of "patent, copyright, trademark, trade dress, trade name or trade secret right and any other intellectual property or proprietary right owned by Wizards."
My intuition, for what it's worth, is that the copyright claim extends further than any trade dress claim - eg changing colours and font but otherwise preserving layout might differentiate a 3PP's formatting from WotC's trade dress, but would still have the potential to be a breach of WotC's copyright.
Anyway, unless I've misunderstood you, I don't think you're disagreeing with my claim that using the OGL to clone 4e could be tricky, if cloning is taken to include the power, item, monster etc templates/layout.
