Salsa usually defaults to exporting data as a Tab-Delimited Text file. Often, though, users are more used to working with spreadsheet data. The good news is that Tab-Delimited Text files will generally open in most any spreadsheet editor!
Once you download a Tab-Delimited Text file from Salsa, you should be able to open that in your spreadsheet editor (such as Excel). Sometimes, your workstation may not be set up to automatically recognize that association (between .TXT and your spreadsheet editor), so I usually recommend opening your spreadsheet program (again, Excel is the most common example), going to (File > Open), and then browsing to the Tab-Delimited (.TXT) file. The spreadsheet program will generally know how to open the file, but it may ask you for the separator, in which case you'd choose 'Tab'. Then, in your spreadsheet program, you can re-save the file in whatever format you'd like.