Short answers, pulled from the story.
Rayner Unwin was an English publisher who served as chairman of George Allen & Unwin, the firm founded by his father Sir Stanley Unwin. He is most significant for recommending publication of J. R. R. Tolkien's The Hobbit in 1936 at the age of ten, and later of The Lord of the Rings, as well as securing the first UK publication of Roald Dahl's James and the Giant Peach and Charlie and the Chocolate Factory.
Rayner Unwin was ten years old when he wrote his 1936 report on The Hobbit for his father's firm. Allen & Unwin published the book in September 1937.
Rayner Unwin estimated that publishing The Lord of the Rings might cost the firm a thousand pounds. His father Sir Stanley replied: "If you think this to be a work of genius, then you may lose a thousand pounds."
Roald Dahl's daughter Tessa gave a copy of James and the Giant Peach to her schoolfriend Camilla Unwin, Rayner's daughter. Camilla's enthusiasm for the book drew Rayner's attention, and he went on to publish both James and the Giant Peach and Charlie and the Chocolate Factory in the United Kingdom.
Rayner Unwin opposed the acquisition of Unwin Hyman by HarperCollins and resigned before the contract was signed as an act of protest. He told friends: "I feel I've betrayed my father."
The Unwin Charitable Trust was established in 1975 by Rayner Unwin using a bequest from his father Sir Stanley Unwin. It supports organisations including the Book Trust and the Publishing Training Centre, and runs a free mentoring programme for small independent booksellers. In 2017 it reported income of approximately two hundred and forty-four thousand pounds.