I wish I could do the voice that goes with it.
As you approach the table just scream “STOP LOOKING AT MY CROTCH YOU FREAKING PERVERT!”
Then walk quietly away. Then when the manager comes over tell him he was licking his lips and you are greatly offended and want him gone.
If he throws you out, half the customers will walk with you.
LOL! Start practicing because you know it will come in handy some day.