Please forgive me if i am stating the obvious, but from the one angle the entire hilt is shot from it at least appears to be a clear depiction of a penis. If that is the case (it might only look that way from this angle) i would certainly lean towards some kind of ritual blade as since i think it would be less likely to have a sexual organ as a hilt for a work blade (i could be wrong). My first though then would be circumcision, but that is not a Buddhist practice AFAIK, so if the blade is indeed from Tibet that would be unlikely. But i still would lean towards a ritual implement.