TSV is less widely recognised by double-click than CSV or XLSX. XML is what many feeds, enterprise systems and older integrations require. TSV is at home in tabular data whose values contain commas; XML is the usual choice for document-like data, feeds and enterprise systems.
The first row is read as column names, and every row after it becomes one <row> element, keyed by those names. A header such as address.city is turned back into a nested address with a city. Numbers and true/false in the cells are written as real numbers and booleans, but values such as ZIP codes with a leading zero, phone numbers and very long ids stay text so nothing is altered; empty cells become null.