Very large and rich sandwiches for 37 kr, hot meal for 8 kr per 100 g. And you don't need student card :). Open during the day on week days, but the hot meal disappears after 1pm, so hurry up.
The small salad bowl is big enough! Take a piece of ryebread on the side - Cut it from the whole ryebread next to the beverages - that's the cheapest way to get a full stomach :)