Someone so obsessed with the minutiae of lower-middle-class good manners that they utterly miss the point of the exercise. The name of the game for these people is not showing consideration for others at all, but merely showing off their own upward mobility in the most vulgar way possible. There are few people more annoying than etiquette freaks, who themselves typically flout the most elementary standards of civilised behaviour every chance they get. A typical etiquette freak would be the character of Hyacinth Bouquet in "Keeping Up Appearances".
There is of course an entire industry of books and other sources supplying the requirements of etiquette freaks, often including such nuggets of folk wisdom as the following, in a book by Angela Lansbury (presumably not the actress): "A lady only has her name in the paper on three occasions in her life: when she is born, when she marries and when she dies."
An etiquette freak will always endeavour to have as many different varieties of knives, forks and spoons for their guests as possible at a dinner party. Preferably all laid out at the same time.