I finally made the holes big enough to actually fit my pens! Turns out, Eddings and other pens are quite huge!
It also features some custom things like a USB-Stick-holder and a headphone-jack-holder.
In the past I used it for a weird headset adapter for my Thinkpad (weird generation where mic and ground was swapped), nowadays it carries a USB-C-DAC (adapter for phones and other stupid devices)
These are the improvised tools I used!
I used "quick helix drills" to softly carve out the big holes. This worked extremely well and had no danger of cracking the wood! Can recommend.
This is the top view:
