Public Meltdowns

Could someone please tell me what to do with a screaming child in the middle of lunch at a restaurant!? We had another meltdown yesterday while we're were out to lunch with family. I know everyone in the cafe wanted to harm me... I could feel the energy! She wanted to be down to run around and do what she wanted, which was not possible at this place. So she screamed and screamed and threw things until we left... and let it be known that we did not get to finish our meals or drinks. So stressful!!!

What do you to to handle this?! I need advice!