Thanks to all who responded with suggestions.  The consensus was to pull
hard to force the catch to release, but not so hard that the plastic panel
would crack.  The alternative of removing the seats, wall panel, etc. seemed
way too much trouble, especially for one with a gambling nature.

My technique was to use all reasonable force with a crow bar, being careful
(and lucky) so that the plastic wall panel would not crack.  Preparatory to
brute force, I had been advised to spray WD40 in the vicinity of the catch
and to firmly push the table in towards the wall a few times to attempt to
loosen it up.  After doing so, I inserted the crow bar on the right (front)
edge of the table, about 4" from the floor, pushed against it, held my
breath, and the table popped loose. For protection against cracking the
plastic, the crow bar had a bit of rag stuffed between it and the panel.

The new locking system will be either by a magnectic catch or velcro.  In
the meantime, the table stays up!