This definitely sounds like a great use case for Retool! I'd recommend checking out some of our docs for walkthroughs of templates and app examples:
https://docs.retool.com/docs/tutorials
https://docs.retool.com/docs/advanced-app-examples
There's also this community post on downloading CSVs from an app:
http://community.retool.com/t/need-to-download-as-csv/7478
And please let me know if you have any questions at all, no question too small!