You do not need to have physical possession of your old prim table in order to migrate it to the new mesh system. As long as your table has been recognized by our servers as belonging to you at some point, our system will “know” that you should have the table, and migration should work. If your table is very old, or has never communicated with our servers for some reason (for example, you never rezzed it out), then you may run into problems. In that case, you can contact us for help.