Three books to be found on John's bedside table, circa 1966. The central thesis of the Passover Plot was that Jesus was not divine, but rather someone who had set out to fulfill the old prophecies of a Savior; the idea being that we are all potentially divine. This was something that cropped up from time to time in interviews that John gave. Of course, his reading of the book also got him into deep trouble, as it led to the comments that in turn led to the Bible Belt turning on the Beatles in 1966. So it goes.
The Psychedelic Experience was LSD "guru" (and alleged CIA double agent) Timothy Leary's handbook for those indulging in psychedelics. It's said that John tape recorded these "instructions" up in his attic studio at Kenwood, and played them back whilst under the influence...the white light...and such nonsense.
Grapefruit, in its first edition, is a very rare and valuable artifact these days. It was given to John by Yoko, and he kept it on his bedside table, apparently finding it amusing and infuriating by turns.