What is the best way to store a bunch of files in iOS

Question

Objective-C

For the program to work, I need to process thousands of small txt files (don't ask why and don't say that it's stupid). I store them in the application resources and successfully work with them (I display the rules, etc.). I constantly need to add new txt files to resources via the Internet. How many files can I add to resources in total? How to add them already in a running application? Maybe you should use core data in general, like how can you expand the data as it loads (as I remember from RSS feeds)?
In general, core data allows you to load only part of the graph into memory and not all. In addition, what are the speeds of data extraction through core data and normal reading of files?
In general, I can not decide how it would be correct to correct the situation. To get away from a bunch of files and the update was normal. Only core data comes to mind or am I wrong?