Could it really be possible that Abby really does not know or is unable to stay on the table when she's approaching it with some speed?
I finally have a real agility table in the backyard, reg. 8" height. I did some playing around yestersday with Abby, I wanted to build up a bit of speed, so I would send her to a tunnel, a jump or whatever and race her to the table, with just slight deceleration, and an opposite arm to cue her to collect. If she slid off, I did nothing, no praise, no correction, just nothing, if she stayed on (in any postion) I'd give her a huge jackpot, treat after treat after treat and just gush over her like she did the best thing ever. After several attempts at this, I'm coming to the conclusion that she really has no idea how to do this. Sure she had some good ones, but I didn't see any improvement.....there's always work to be done!