It's possible and it works very well. Proceed as follow:
1/ Select your language and the module you'd like to translate offline, for example, health_icd10.
You should see two arrows on the right side of the screen:
- one for downloading your file for offline translation
- one for uploading it
2/ If you don't see them, they may be hidden. In this case, you should see the following double arrow:
on the right side of the screen,
Click on it to see the arrows for downloading and uploading your translation file.
I use Poedit for offline translation and it works perfectly.