My apologies, haven't been here in a while, don't know GAF or that it was an antique, which now appears to be in question.
The substrate needs to be identified in order to proceed. Since the bubbles feel solid and not hollow, I'm a bit more suspicious. I've seen only particle board or MDF swell enough to lift the veneer and even split the veneer. It can get in through oak veneer quite easily since its an open pore wood.
As for re-veneering, I'll offer that I have used PVA glue (allowed to dry first) and a hot iron and it works quite well. Although not ideally suited for large areas like a table, it is possible to apply the veneer in workable strips and do a section at a time. I've repaired veneer on a table top where a whole strip came loose using this technique with satisfactory results. If you're careful about the edges, it is doable.
Last edited by DrRobert; 06-06-2019 at 12:47 PM.