Welcome!
FYI, Science Diet is not the best food there is, you might want to consider switching her. Also, just to see if it's an issue, you might try free feeding her and see how much food she actually eats.
As for why she likes human food without eating any... well, they have noses.
I guess it can be different for different dogs. Thor sits on my desk while I work and will not beg if I eat at my desk. Every time he tried at first, I would just "sweep" my arm to push him back to his bed and he got the idea.
I would implement a "one strike and you're out" rule. If she does ANYTHING you don't like, put her in her crate for a minute. Be prepared to do this literally thirty times in a row, and she will probably get it permanently.
Alternately, you could crate her with a bully stick or something else she can attend to while you eat.