The word "Torah" is a tricky one, because it can mean different things in different contexts. In its most limited sense, "Torah" refers to the Five Books of Moses: Genesis, Exodus, Leviticus, Numbers and Deuteronomy. But the word "torah" can also be used to refer to the entire Jewish bible (the body of scripture known to non-Jews as the Old Testament and to Jews as the Tanakh or Written Torah), or in its broadest sense, to the whole body of Jewish law and teachings.
From Judaism 101.
The link to the Golden Dawn would be via Kabbalah, as it is impossible to study the mysteries of the Kabbalah without first studying Torah (in the wider sense). But that's only the first step. A Kabbalist studies deeply, but alongside study, meditates and visualises in order to apprehend the mysteries from the inside. The High Priestess is the guardian of those mysteries, especially of the mysterious, unwritten, inner Torah, which is the aim of all Kabbalists to discover for themselves. She is both book-learned and beyond books - she has travelled into the inner meaning of Torah, the inner law of God and the Universe.