What does "Lechem ha'Panim" mean?
Rashi: It refers to the two sides of the Lechem ha'Panim that were upright, 1 like two faces that could see the sides of the Mishkan.
Ramban #1 (citing Ibn Ezra): It is so-called with reference to the "Lefanai Tamid" in this Pasuk.
Rashbam: It is an expression of Chashivus - Bread that is fit to place before princes. 4
Hadar Zekenim (23): "Panim" is always at least a Tefach. This teaches that it was a Tefach thick.
As the Gemara says in Bava Basra, 28b "Someone who wants to become rich should turn to the north'.
How was the bread arranged on the Shulchan?
Hadar Zekenim (23): The bread was 10 Tefachim long and five wide; when it was folded, also the length was five. Two piles of six breads each were side by side on the Shulchan. Their width filled the length of the Shulchan, and their length filled the width of the Shulchan.