There wasn't any here and the reason he would eat it isn't present either. But it stops the topic which is why he wants.

Vader finally shifted, straightening up to his full height, and reached down to take her (surprisingly) gently by the shoulder and ushering her out into the open, Vader appearing to follow rather than him leading. "I work with Imperial Intelligence occasionally, I would be remiss if I did not recognize your face." In fact he's pressing her back toward the food and it's napkins and plates.

Despite the comment, he doesn't act like a threat.