The only help I have found for this is to delete building blocks and let Word regenerate new ones which will wipe out all of the custom built tables. I also found this
Fix it for me

Migrate your custom templates using the easy fix tool.
The easy fix tool fixes all Office programs at the same time. You don’t need to specify the template location in each Office program.
However, the easy fix tool doesn’t help you to set a new location. It only migrates to the Custom Office Templates folder under My Documents. To set a new location, see the "I'll fix it myself" section below.

Does this work in this situation? We are trying to get people upgraded but there are some who will be on 2010 right up until just before April deadline for the drop support by MS.