My initial sense was to open the file and let the user start working on it, treating it like an editable table, but that implies that changes to the data will be made in real time, and that's not the case for your system.
Instead, because there's a formal import/export process, you should treat the .tsv like a file and open the containing folder (or give the user a shortcut to quickly open the folder, as we see with downloads in programs like Chrome and Slack). The user then has some orientation on where the file is located, for when they move or re-upload it later on.