I have done exactly that. Only had to do it once. “Settle down or we will go out to the car and wait for everyone else to finish. “ My child did not, so we left. Sat in the car with no toys no radio, no food. “Will mom bring my dinner home?” - “No. You don’t get dinner tonight. Neither do I, I’m sitting out here with you. “
Done exactly that. Stop the car and nothing happens until they behave. It works!
My 1 yr old grandson is one of the Babies Who Lunch. He feels the vibe of a fine restaurant and does his charming baby thing, enchanting one and all. He will find that being a terrible two is not OK when we go out.
And, yes, he loves his Mimi.