Nobody will guess the purpose of the third object. It is impossible to guess, in my opinion, especially since the Russian “Writing controller” is poorly translatable. Although in general it is clear: we have a
clamp for fingers while writing texts.
If you look at the picture (the quality is traditionally unimportant, unfortunately), you can see two small blymbochki on the index and thumb. That is, the required length is set on the clip, across the width of the fingers, then the clip is taken inside the palm and put on the index and thumb, pressing them tightly against each other. As a result, fingers do not get tired during work.
The controller of the brand "Gordon", an indispensable device for the precomputer era.

I would not give up on something like that, which allows you to relax your fingers while working on a computer keyboard. Twenty years of continuous clatter on the keys affect: begin to ache the joints on the right hand.