Rashi in Mishlay (31,31), the source for the song, says that the song is talking about the Torah. Where in the text of the song itself are the proofs for this theory and explanation of how the text indicates it?
Rashi (31:31). He says that you can explain it as a mashal. He then starts explaining each pasuk once again.If you follow his commentary he explains how the text can be explained either as speaking of the Torah or about those that are asukim (involved) with the Torah.
In lev Eliyahu from R' Elya Lopian tz"l (written by R' Shalom Schwadron tz"l) he quotes a story he had with the Chofetz Chaim tz"l. As the Chofetz Chaim tz"l was singning Aishes Chayil he stopped by the words "Noda bashearim ba’la, Beshivto im ziknei aretz" and said ba'la is referring to Talmidei Chachamin as they are the "Noda" - the ones who know Torah