Pharmaceutical companies seeking to peddle their wares often provide small bribes by way of coffee and sandwiches. Medical students are usually permitted to partake of the morally ambiguous offerings. You will need self denial to create a good impression. Make sure that you have no more than one sandwich. Although no-one will mind, you will have to endure misty eyed consultants regaling you with anecdotes concerning student hardship in years past, if you reach for a second sandwich.
Coffee is the really dangerous area.
Spillage is a potential problem because of a slight worry that you may scald yourself. More worrying is the angry registrar with sodden notes. In the absence of a drug lunch everyone brings his or her own lunch. The last time most students did this is probably at primary school. The clinical lunchtime meeting is not dissimilar.