I haven't had this problem. I've had to switch tables because people won't pass the cranberries :( but I've always been able to eat at the new table. And it still counted for the achievement (Pilgrims Paunch).

That's because it's not you who has the food, it's the spot at the table. If you move to another table, your plate there is empty.

I was online when this event started the other day, and yes none of the tables outside SW were working. Lots of sad and angry players. A GM apologized in chat. Several hours later they were working perfectly. :-)

Weird though, I tried with a different toon the next day and I swear the mechanics of the table "vehicle" had changed subtly. Before when you passed something and didn't have a plate selected it would allow you to click on one via the glowing blue hand cursor; but a day later it just defaulted it to your plate, and you had to click on a chair before hitting the pass icon. Maybe this is why others weren't passing the servings... because the mechanics are a little awkward?

Another tip for the bountiful harvest quest: if you are in Outland, just head over the Telredoor (sp?) in Zangermarsh on Alliance side (I'm sure the Hordie town in ZM also has this)... there's a working table there and never seems to be anyone on there. You can pick up the quest right there, bounce from chair to chair, and get it done in a minute or so.