After digging through the strata of 21 Dirty Tricks at Work and The Peter Principle, we are now at the level of paleo-management-book-parody. The earlier we go, the less helpful the books are, but the funnier they are.
Stephen Potter is the inventor of 'gamesmanship', which (unlike sportsmanship) is the art of winning through any means possible without actually cheating. The precursor of 'talking trash', as it were, but in a more refined age. 'One-upmanship' extends this concept to getting one-up on other people in everyday life. It's extremely funny.
All the pettiness of modern life is there, in parodied form. The chapter on wine recommends pretending you have a wine cellar by going into the cupboard under the stairs, and clomping around a bit. The section on attending meetings suggests a response to a good idea of saying "Well", pausing to look hard at the chairman, as if you have a shared secret, "there are definite reasons why that is going to become impracticable fairly shortly, aren't there?". International rivalry with the Americans, pretending to be an experienced mountaineer with setting a foot on the mountain, all this and more!
Obviously it's very dated in places. Many of the names and techniques are lost on me. There are lost skills, such as how to irritate people with a pipe. However, this adds to the charm, partly because it's such a clear slice of history, and partly because everything is so wonderfully understated. Comedic evil in tweed.