Custom dropdown menu in wordpress edidor

So, I need help. I was requested to make a dropdown choice for certain cells on our wordpress site, in editor, not on frontend. Im using tableberg plugin to build my tables and for certain cells in the table, i would need to have a dropdown choice for that option loaded from database, for example customer, production line etc. I have an example page that will be duplicated and edited for 1000+ times so this dropdown selection for some cells is a way to make job for site editors easier making all of the pages. What would be the simplest solution for my problem?