My current boss does shit like this and it's repulsive. Imagine a man with a sinus problem eating an apple with his mouth open and talking between bites. That's lunch for me every day.
Slurping is nothing. What's really annoying is when people yawn like fucking lions. You know, that stuff you see in cartoons where after they yawn a kind of clapping noise with their mouth and tongue. WTF is that shit?
I know your pain. I'm only glad that I never had the traditional 'eat the at the table together' every night experience when I was younger because I would have probably gone insane.