Question

Why had oliver end up spending his birthday locked in the coal cellar

Answer 1

Oliver needed more food. He was sent to the coal cellar so that he could get food and find a cure to his hunger.

Oliver, an orphan kid (child of Edwin Leeford and Agnes Flemming) is the kiddie hero of the novel. A dear, appreciative, tender kid who "as opposed to having a too small feeling, had rather excessively." He is additionally a connection among three distinct universes portrayed in the novel – the workhouse, the crime scene, and the universe of the sophisticated white collar class individuals.

He is, in this manner, more a symbol than a completely individualized character. In the opening sentence of the novel, Dickens portrays him as a "thing of profound morality"