I'm not sure specifically as I haven't read this story directly. But it might be about someone named Cock Sparrer and their experience related to a very special or desirable seat in a house.
The title 'the best seat in the house a cock sparrer story' is rather mysterious. It could be that the story follows Cock Sparrer as he discovers or claims this so - called best seat in a house. It might be a story of competition, if others also want this seat. Or perhaps it's a story about the memories and events that take place while Cock Sparrer is in that seat, which make it the best seat in the house for him. It could be a humorous or serious story depending on the nature of Cock Sparrer and the events that unfold around this seat.