In the Inspector, \n will always be displayed as \n unless you have “Parse Escape Characters” enabled in the Extra Settings panel. In such case it will be processed as a linefeed.
In a string, C# will convert “\n” into a line feed which will then be handled as such by TMP.
In a string, “\n” tells C# to process the string as a literal and thus is becomes / displays as "" + “n” or two separate characters.
Most of the time when you use some text editor or xml or excel / google spreadsheet, etc. the “\n” gets escaped to “\n” which then results in the "" + “\n” instead of a linefeed.
BTW: If you were to create a simple script that iterates over the string from Google spreadsheet, you would see how the “\n” is escaped into “\n” or literal and not char(10) / linefeed.
P.S. In the TMP Settings file, the default behavior of newly created objects and whether or not Parse Escape Characters will be enabled by default can be set.