...You are with your wife or SO and suddenly a single BG with a gun comes in. The thinking here is he believes classy restaurant=loaded patrons. he orders everyone to freeze and remain seated and threatens to shoot anyone who gets up.
He proceeds to move from table to table demanding pearl necklaces, watches, wallets, anything he can get quickly. he is getting close to your table, by this time you've already quietly draw your firearm under the table and it now rests on your lap in your strong hand. You don't know if he is stable or if he will shoot up the place before leaving, but for not it seems like compliance is working with other tables.
He is now at the table next to yours, he has his back to you as he stands and demands valuables from the neighboring table. Since everyone is seated and he is standing with his back to you 6 feet away you have a clear shot..
do you take the shot? or do you hope for the best and comply? Do you wonder what happens if he discovers you are carrying a gun?