Matpakke is a tradition in Norway going all the way back to the 1930´s. It is a prepared meal wrapped up and brought to work from home.
In Norway all children bring matpakke (or nistepakke) to school, and eats it in their lunch break.
A typical Norwegian matpakke is usually made out of bread with something on the top like cheese, ham etc., and wrapped up in sandwich paper, or in a lunch box.
It is also common in Norway to have organized milk- and fruit orders at the schools in addition to the lunch brought from home.
Read more about the Art of Matpakke from this BBC article: