Apparently in the Victorian era, taxidermied dead pets were the new black. So at the time it wasn't at all weird. Chuck just opted to preserve the paw, which was used as the handle of an ivory blade engraved with "C.D. In Memory of Bob 1862". That represents a level of intimacy some people don't even have with another human.
As disappointing as it is to find out that the writer of David Copperfield was a crazy cat person, it's still kind of sweet (and also weird) that he never wanted to lose the warmth of Bob's furry embrace. [NYPL via Slate]