It takes Hermione a long moment to connect the sound of the voice to the fact that she's the only other person sitting at the table and he must, therefore, be talking directly to her. It snaps her out of her thoughts for a second and she looks appropriately apologetic.

"Sorry?" she asks. Then it dawns on her belatedly what he's said and she gives him a small smile. "I've eaten worse, I just got lost in thought a bit, I suppose, sorry."

He does make a good point, though, so she looks down at the food again for a second before meeting his gaze once more. "I'm Hermione," she offers. If he's talking to her first, then the likelihood is that he's attempting to start a conversation, so she might as well engage it. Maybe he's been here longer and has information she can use to propel her own investigation further. Hermione will take any help she can get.