P.K.
I'd calmly explain to him, (even at only 9 mo's, kids understand more than we give them credit for) that his behavior is unacceptable, and if continues to scream, then he will be ignored. Then, I would ignore him. If he's at the table, remove him from the table and let him scream. That's telling him that he is also not allowed to act that way at the table either. It's basically a tantrum. My daughter has tried pulling that before, and she screams at me in anger right in my face, and I just walk away and let her scream and go on as if she weren't there. It stops very quickly because they aren't getting the attention they are looking for. Everyonce in a while, she'll do it again, and I just do the same thing, and then I don't see it for a while again. It's like she needs reminding that her behavior will not be accepted. Eventually, she comes to be crying and looking for hugs, and I let her come to me after she's done freaking out. Good luck, and try to be consistant. That's the hardest part.