To me, "return" implies a "go back" action (like "backspace"), which is the opposite of "enter", so naming the key the latter makes more sense. Plenty of TUIs used the arrow keys, Backspace, and Enter for navigation. Also, the text is nicely readable but none of the images are viewable.
As I understand it, "return" is a shorthand for "carriage return" - as on typewriters, going to a new line meant returning the carriage to its original (start of line) position.
Line Feed moved the paper up one line, Form Feed moved the paper up by a "form length" or, in the case of chain printers, to the particular position on the chain that was synchronized with the perforations on the paper itself.
The carriage return physical device on the typewriter combined moving the carriage (which could be done by hand) and the rolling of the paper up one line (which could also be done by hand) into one convenient motion.