What TSV is
TSV is CSV with tabs instead of commas. Because tabs almost never appear inside a value, quoting is rarely needed and the files are easier to read by eye.
Bioinformatics, log processing, and anyone who has copied a block of cells out of a spreadsheet: the clipboard format is TSV.
What MediaWiki is
MediaWiki table markup opens with {| and a class, marks headers with an exclamation mark and rows with |-.
Wikipedia editors and anyone running a MediaWiki install.
What changes when you convert TSV to MediaWiki
The tab is unambiguous, so there is no delimiter to guess. This is the most reliable of the delimited formats to read.
The wikitable class is applied, which is what gives the table borders and header shading on Wikipedia.
What carries over from TSV to MediaWiki
One property of the TSV has no home in MediaWiki, and it is worth knowing which before you convert.
MediaWiki marks its header cells differently from its data cells, so the first row is written with that marker.
TSV can be read one record at a time. MediaWiki has to be complete before it means anything, so the whole table is held in memory while it is written and a file that gets cut off part way through is not partly usable - it is unusable.
The identifier 007 comes out of the MediaWiki as 007. Reading it as a number would have made it 7, and an id that changes value is worse than one that stays text.
The role "Analyst, data" survives with its comma, in one cell rather than split across two. That is the first thing to check in any converted table, and the usual place a MediaWiki file goes wrong.
The quotes around Jonah "Jo" Pryce are left as a plain quote character in the MediaWiki.