This sort of tasking currently isn't easy to do in ODK. It's sort of related to these features below, but it isn't exactly the same.
- Enable Case Management/Preloading
- A dynamic form data lookup locally without server synchronization
- Dynamic choices within a single form and across multiple devices
You could add code to Collect where if the CSV changes, it re-generates the SQLite database (the file with .db). Or you could add the data directly to the database. Either way, it'd be pretty fragile...
If this is a feature you really want, describe the underlying problem in greater detail at https://forum.getodk.org/c/features and we can gather feedback from the broader community.