As a young man, Tom gambled and caroused quite a bit, to the extent that he lost his father the parsonage connected to Mansfield, the one that Edmund was destined to have. Instead it passed to Dr. and Mrs. Grant. Tom was sorry, but there was nothing they could do to rectify it besides getting rid of the parsonage.
As punishment, and in order for Tom to learn a few things about the world, Sir Thomas and his firstborn left England for Antigua, in order to look at some land that Sir Thomas owned in that part of the world. After a while, Tom returned to England without his father, but brought world of Sir Thomas's continual good health to his family.
Tom is portrayed as being irresponsible and light-hearted. When his younger cousin Fanny first arrives at Mansfield, he teases her and laughs at her, but not in a cruel way.