This is an American folk expression, describing a story which isn't believable and told for fun. A tall tale includes massive hyperbole, often impossible situations, and is intended to stimulate the imagination. In common usage, tall tales are made up, or quoted, and swapped between parties on an ever increasing scale of improbability.
Examples of Tall Tale:
|First Speaker: Yeah, I did the plumbing for Atlantis and the Great Pyramid of Cheops. Main problem was where to put the tap on the pyramid.|
Second Speaker: You call that work? I had to iron the Great Wall of China, and fold it properly.