I originally saw a need to keep my Dell Dock (like a WD15, WD19 dock) cable from falling to the floor, as it was laying on the edge of my work table. So I designed this small cable holder where the intention is that you use something like double sided tape on the big flat surface, and attach this to the edge of the table, close to where your cable runs. The opening is a bit smaller than the inside, ensuring that the cable does not pop out on its own.

I say originally it was designed for this, but I realize that cables such an a CAT5, 6 etc. LAN cable, or maybe a small power extension cable or similar could also fit inside. Any cable with the approx. dimension / radius of 6 to 6 ½ mm.