The early Trek novel "How Much For Just The Planet
" (as you might guess from the title) had a nice amount of humor in it. The modern Trek novels are down right grim.
missing in post-TOS series to a great degree. There are occasional funny pieces, A Fist Full of Data's comes to mind. Plus there are scenes that I think were supposed to be serious that are quite funny. Janeway discovering her tiny "spirit guide" while drugged up on Chakotay's electronic peyote always get a giggle out of me, but I don't think it was intended to be funny.