Numbers.app will open .tsv file beautifully, recognizing tab as seperated characters.

However, if opened directly with MS Excel, .tsv file will be treated as csv (comma seperated values).

So,

Excel import

In MS Excel, create a new .xlsx file.
Data > Get External Data > Import Text File
In Text Import Wizard,
- Select your .tsv file
- Next
- Next
- Finish
- Import

Voila!

If you want to remove a line, just delete the EDL from that first column. So your lines can still stay in your way for future reference.

Plus, copy a region from your spreadsheet in MS Excel and pipe to tsv2roughcut works fine.