In reply to Bimble:
I was in a restaurant once when some little scrote was just running free. After about the 3rd time of him crashing into the back of my chair, I stuck my arm out on his next lap and told him, politely but firmly, to go and sit down. Didn't see him again
I have friends who have got things like a bottle of wine on the house because their kids were so well behaved.
My parents took my daughter and my cousin's boys (aged 3-7) out for the day on Monday and had lunch in a cafe where, it being half term, was pretty chaotic. The elderly couple sat on the next table congratulated my parents on how well behaved our kids were compared to some of the other hooligans.
So, basically, it's not impossible to have well-behaved kids at lunchtime.