AIBU to want to bop them on the head with the nearest suitably pointy/heavy object? And do you know anyone who does the same?
I have a family member staying and he does this. He always has. He was just eating a takeaway and commenting on it as he goes 'Hmmm. Could be a little spicier. That's a good size piece of chicken there. Where is my napkin? Oh, yes, it's here. I think that I'll have the fried rice next time. I'm not sure that the sauce works with the noodles... He isn't on fucking Masterchef! There's no need for it.
He does this with everything though. If he cleans he has a running commentary on what he's doing and how seemingly difficult it is for him, as though someone supposed to say 'I'll do that'. 