TSV is less widely recognised by double-click than CSV or XLSX. XLS opens in copies of Excel older than 2007. TSV is at home in tabular data whose values contain commas; XLS is the usual choice for compatibility with very old copies of Excel.
Numbers and true/false in the cells become real spreadsheet values rather than text, and the data lands on one sheet named Sheet1. The old XLS format holds at most 65,536 rows and 256 columns per sheet; a bigger table is refused and the page says so (XLSX has no such limit in practice).