I made these cable trays to neatly hold all the power, network and HDMI cables for our home office.
It also includes a tray for transformers from laptop chargers.

I used 2 sections of Ø6.3mm Solid Galvanised Steel Bar, and mounted to the bottom of the desk with 3.5 x 16mm Black Countersunk Timber Screws.

Suitible for any length of desk, as the cable trays clip in, and you cana print as many as you need to fill the space.