A-To give notice to another person by knocking with the knuckles upon a table top when frustrated with said person.
B-To mark one's territory when concerning a loved one, like a dog pissing on its front lawn.
C-To make one's presence felt.
I was at the bar with Ronelle and she started talking to these three guys at a table. So, as I walked past, I table knocked those mother fuckers. They all looked at me with so much fear and confusion in their eyes. Mainly confusion.