Yes, This is how I would do it.
1. Pry the pocket liner loose and pull it down and out thru the bottom, then get under the table and pull the cloth loose from under the slate in the pocket area and the edge of the slate in the pocket but not the top edge of the slate.
2. Get some 2 in masking or blue painters tape and tape over the entire pocket area from the top,under the rail and on the playing surface(so no overspray gets on the cloth ),
3. Then get back under the table and push the loose cloth up against the tape (so the top side of the cloth sticks to the tape), then spray glue the underside of the cloth and the edge of the slate,go back up top and remove the tape, wait 3 or 4 minutes and press the cloth to the edge from the top . Repeat if needed.