I came across one mapping table where its each column will have multiselect dropdown on the UI so user can select one or more records on each column. below somewhat UI would look like where maildID is unique and rest all columns can store one or more value per row.

I’m trying to design a database for an e-learning system, but I’m wondering if what I’m doing is too complicated and if it can be used when coding an e-learning website or not.
Please take a look at my database