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 LaTeX is
A LaTeX table is a tabular environment: a column specification, ampersands between cells and double backslashes at the end of each row.
Academic papers, theses and anything typeset with LaTeX or written in Overleaf.
What changes when you convert Plain Text to LaTeX
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.
Rules are drawn with booktabs by default, which is what most journal templates expect. The characters LaTeX treats as special, & % $ # _ { }, are escaped so a value like 50% compiles instead of ending the line.
What carries over from Plain Text to LaTeX
One property of the plain text has no home in LaTeX, and it is worth knowing which before you convert.
LaTeX marks its header cells differently from its data cells, so the first row is written with that marker.
LaTeX is the end of the line for this data. Reading the table back out of it is a separate and much harder problem than writing it, so keep the plain text if you will need the values again.
The identifier 007 comes out of the LaTeX 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 LaTeX file goes wrong.
The quotes around Jonah "Jo" Pryce are left as a plain quote character in the LaTeX.