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 Box-Drawing Table is
The same grid as an ASCII table, drawn with Unicode box-drawing characters instead of punctuation.
Terminal UIs and documentation where the output is known to be UTF-8.
What changes when you convert TSV to Box-Drawing Table
The tab is unambiguous, so there is no delimiter to guess. This is the most reliable of the delimited formats to read.
Prettier than plus signs, and safe anywhere the reader's font has the box-drawing block, which is almost everywhere in 2026.
What carries over from TSV to Box-Drawing Table
TSV records 2 things about a table that box-drawing table has no way to hold.
A line break inside a cell ends the row in box-drawing table, so line breaks are replaced rather than carried through.
box-drawing table 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. box-drawing table 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 Box-Drawing Table 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 Box-Drawing Table file goes wrong.
The quotes around Jonah "Jo" Pryce are left as a plain quote character in the Box-Drawing Table.