Malm Desk Cable Hook
This thing was made with Tinkercad. Edit it online https://www.tinkercad.com/things/8n3WhgS2Wdc
I created this to run cables for my headphones under my Ikea Malm desk so they don't hang over the sides or use space on the top. I also use another to run a charger cable up from the back of the desk. You can reverse the model if you need the hook on the opposite end.
I made the tolerances fairly tight so that it sits very snugly. So far it's working out well.