How to Create multiple Database Tables and use them In one Controller

Question

I would like to create mutliple database tables and control them in one controller
what would be the best approach for doing that,

I thought about Creating multiple Connectionstrings (and Data Contextes, and multiple Services in the Startup.cs)
but once i start scaffolding them i can only control them in differend controllers.
And it would not be scalable if i want 20 database tables

It might better to have one Database table that links to different tables

but im not quite sure how to do that or if thats even a good idea?

and how to link the Models to those tables