To tempt people into purchasing a snack to accompany their reading. But I am sure you knew that already. ( Is he being a bit patronizing? Absolutely. Does he care? Not one bit. )

Why do you ask? Has something taken your fancy? ( Food or literature, both of questionable quality.

While he's at it, as he's reminded of Gumshoe...)

I am sure you see the folly in entrusting your possessions to the detective, now.

( He's not saying that Gumshoe can't be good for other things, just that packing and oversight is not one of them. )