Here is some sample code for loading multiple csv files at startup, as part of a project I had lying around ...
To get a table of all US states and cities, I suggest the US Census Bureau.
https://www2.census.gov/programs-surveys/popest/tables/2020-2021/cities/totals/SUB-IP-EST2021-POP.xlsx
would need a spreadsheet program for conversion to CSV format.
I had LibreOffice lying around, so I tried a single column copy, to get full CSV text I could paste into NotePad for upload into your Project's Media folder.
Here is a sample project with table filtering ...