No, that isn't a misspelling of the word Sudoku, the numbers game. Tsundoku is Japanese and means, "acquiring reading material and letting them pile up in one's home without reading them". For years I've called myself a bibliophile which is "a person who collects and has a great love of books". That is still me, too, but now I have a new term to describe the hundreds of books in bookcases lining the walls of my basement, my living room, my studio.
I find it fascinating that everything we do, no matter how unique it may see to us, and even if no one in our circle of friends and family ever encountered anyone else who did this unusual thing that you do, you can be assured that someone else out there does it, and there is a name for it. That was definitely how I felt when I heard a contestant on Jeopardy not only say the name "Tsundoku" but Alex Trebek agreed he, too, suffered the same affliction.
To me there is no such thing as owning too many books.