The Hall was a center of social interaction for the Norse, especially Norse rulers. They gathered there, held court, ate, told stories, drank beer. It was a display of a king's, or thane's, wealth if he had a splendidly decorated hall.
"I was nurtured in the kingly hall, I was the joy of many in the council of men. Life I enjoyed, and my father's wealth, five winters only, while my father lived." The Poetic Eddas, Oddrun's Lament