What Plain Text is
Plain text here means columns lined up with spaces, the way a command line tool prints a table.
Terminal output, log files, fixed-width exports from older systems.
What INI is
INI is the oldest configuration format still in daily use: named sections, then key equals value lines.
Windows software, PHP, Git and a long tail of tools that never moved on.
What changes when you convert Plain Text to INI
Two shapes are handled. If the same character positions are blank on every line, those gutters are treated as column boundaries, so values containing single spaces stay intact. Otherwise the lines are split on runs of whitespace.
Each row becomes a section named after its first column, with one key per remaining column.
What carries over from Plain Text to INI
One property of the plain text has no home in INI, and it is worth knowing which before you convert.
INI has no header row. The column names are repeated as keys on every record instead, which is why the result is bigger on disk than the table it came from.
The identifier 007 comes out of the INI 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 INI file goes wrong.
The quotes around Jonah "Jo" Pryce are left as a plain quote character in the INI.