Summary

I have made a similar design however I came across rgonclaves's which had a much better solution to the grove hence this is marked as a remix. However I have also removed the groove on one of the sides to allow for a deeper grove on the one side which holds the cables in more securely.

Holds 6 cables with a maximum wire diameter of 5mm. However I included the 3ds and step files so feel free to modify to your needs.

In the 3ds I added the 2 variables "number_of_holes" and "cable_diameter" for those unfamiliar it is under(in fusion 360):

Modify>Change Parameters

This model is designed for a 15mm double sided tape I used this one