What is this tool for? Likely something to do with cables? I found this thing in a box of bicycle tool mix I got some time ago. In the end this was the only one I could not identify, so I am asking here: What is this thing and what is it used for, please? I think it might be somehow used to manipulate with the cables. But since I do not know the name of the tool, I can’t look up for more info



Thanks!
That's a spoke wrench, for turning spoke nipples.  The benefit of this design is that, as opposed to the kind with an arm coming out each side of a central body, the force from your fingers is spread over the faces of the disk, meaning you can apply more force and it hurts less.  

I'm not certain, because I haven't used it, but it also seems like it would be easier to keep your grip on the wrench; the other kind is prone to being fumbled and dropped as you turn it (at least when I'm the one turning it, it is).

Here's an example: https://www.amazon.com/KLICKfix-Rixen-Kaul-SPOKEY-professional/dp/B003ZRWA4Y/