You seem to have \!n instead of \!N.
For me it seems to work fine with this example (using Windows and JMP16).
Names Default To Here(1);
dt = Open("$SAMPLE_DATA/Big Class.jmp");
nw = New Window("a",
teb = Text Edit Box("", << Set N Lines(20))
);
//paste values to teb...
//get values
teb_values = teb << get text;
teb_as_list = Words(teb_values, "\!N");
Show(teb_as_list);
//{"KATIE", "LOUISE", "JANE", "JACLYN", "LILLIE", "TIM", "JAMES", "ROBERT", "BARBARA",
//"ALICE", "SUSAN", "JOHN", "JOE", "MICHAEL"}
Also copy-pasting from JMP datatable to Notepad++ with "View all characters" enabled, CR (Carrier Return) and LF (Line Feed) seem to be added at the end of row/line:
-Jarmo