Two details of Percy's study?

From the text:

They consisted of bedroom, dressing and reception room, and at the extreme end of the landing, of a small study, which, when Sir Percy did not use it, was always kept locked. His own special and confidential valet, Frank, had charge of this room. No one was ever allowed to go inside.

Laughingly she had always declared that he strictly excluded all prying eyes from his sanctum for fear they should detect how very little ‘study’ went on within its four walls: a comfortable arm-chair for Sir Percy’s sweet slumbers was, no doubt, its most conspicuous piece of furniture