Something similar happened to me a few years ago:
I was with a friend in a sports bar type joint, and this same type of "prank" was pulled, only dude tried to reach into my plate. I intercepted his hand and stood up and calmly asked him what his problem was.
He was kind of shook. He kept claiming it was just a joke. I told him that I did not find it humorous at all... just kept a grip on his wrist with the

face the whole time.
His boy started poppin' some shit about how they were only joking and I needed to relax- i told
him that I came
here to relax and now that relaxation is being interrupted... the whole time with the iron grip on dude's wrist. I invited the shit- talker to the parking lot to discuss the issue further, and he accepted. Just as he was standing up, his girlfriend got in his face, saying "you are MY man! you are NOT fighting!" They were drunk as hell, and myself and my dude were not. It probably would not have gone well for them.
about that time the waitress showed up, looked at the situation and asked the WHITE GUYS what was going on (

). (I still had dudes wrist in the kung-fu grip) they told the waitress how they were just joking and all that, I just asked her if it was common practice here for folks to reach into each others plate, cause the guy a few tables over had a cheesesteak that I was dying to take a bite of. The waitress chilled everyone out,( I finally let the guy's wrist go) and the white dudes were trying to shake our hands, and buy us drinks and apologize, and I just let them know that the best thing that they could do would be to turn around and enjoy their dinners with their lady friends, which they finally did.
anyway, I honestly feel like they wouldn't have thought it would be funny or whatever if we were white guys... possibly the same thing in your case. do you think the same thing would have happened if you were white? In any event, it was really no big deal,
no need to go shooting up the place- reminds me of the seinfeld episode in the chinese restaurant where Jerry offers Elaine money if she will walk up to someone's table, take food off the plate and eat it. White people think that kind of shit is funny....
* and oh yeah, I was pretty calm the whole time and badass (imo) because I knew my boy was just waiting for some shit to jump off, he was a coiled spring, a cobra waiting to strike. I had control of the one, so if the other tried to sneak me, I knew he had my back.
On the way home, of course that was all we could talk about, and he says; "You know, I was down in my plate and didn't even know what was happening until you challenged that guy out to the parking lot"