There are hundreds of stalls, vendors, and traders with every type of deliciousness you can imagine. Fresh vegetables, exotic fruits, sliced meats, my absolute favourite olive bar.
There is food from every corner of the world and you can make a meal out of the sentence: "can I try a sample of that, please?" In one direction there is Paella being stirred up in a bathtub-size pot perfuming the air. To your left is a stall just for oysters. To you right, Italian chorizo and Spanish ham, cured and dried, and sliced paper thin right off the bone for you to snack on while you browse. Hmm.. that yogurt I had for breakfast suddenly seems completely inadequate...
And speaking of cheese... Be sure to visit Neal's Yard Dairy while your under the bridge. It stinks to high heaven but it is the perfect place to pick up a hunk of salty parmigiano reggiano to eat with the proscuitto di parma you picked up a few vendors back.
The Borough Market is always bustling and you could spend hours getting lost in the labyrinth of stalls. In the summer I recommend a glass of Sangria while you meander around in a haze of mixing aromas. Follow your nose and the rumbling in your stomach to the next stall and the next and happily slip into a food coma.