My paperstone is 11 3/4" x 11 3/4". Don't know the weight but it's very stable for me. The rubber feet keep it in place.
Regards,
Bob Hardison

I recently sharpened a Randall Model 2 6" Stiletto Fighting knife on the WE. Although not the knife you have, it presented a similar clamping problem. I used some 1/16" electrical rubber tape on both sides with success in holding the knife in place. I did not want to clamp on the flat portion of the blade because it would been too far toward the hilt & therefore create an extreme shallow angle at the tip of the blade.

I have since left the rubber tape in place to prevent marring blades. Hope this is useful.

Bob Hardison