If you’re always going to load it all into memory, then I’d just use a text file (or other flat file, such as JSON, etc) and be done.
If you’re going to constantly searching that data, filtering, etc, then SQL (especially something like sqlite) is a perfectly valid way to go, and probably quite a bit faster than writing your own routines. (Assuming there really is a lot of data. Thousands of lines doesn’t seem like a lot to me. But then, I work on databases with millions of rows, so I might be jaded.)