StrangeBookBob,
A difficult undertaking. Off the top of my head I can think of only three consistently strange book authors: Ronald Firbank, Ivy Compton-Burnet, and Paul Bowles. (Some people would add Thomas Love Peacock, but I do not find his books all that strange - ditto Hermann Hesse.)
I recall reading a book in high school that I thought really strange, but I cannot remember the author, title, or even subject matter at this point (it was set in North Africa where most of Bowles' books are set - there must be something about North Africa).
SpottyMemoryBob
PS - William James is supposed to have said of his brother, "Henry writes better and better about less and less." I like one or two of Henry's book, but most of them are pretty strange - not in the class of the above triumverate - more in the class of Peacock and Hesse.
PPS - have you read
The Quest for Corvo: An Experiment in Biography (New York Review Books Classics) by A. J. A. Symons and A.S. Byatt (Paperback - Mar 31, 2001) 6 new from $24.89 4 used from $24.85 (9)