The first page of Exodus in the Complutensian Polyglot can be seen here. Click on the image once to move to the image only and a second time to enlarge it.
In the center of each page is a narrow column with the Latin Vulgate. To the outside of the Latin (to the right on right-hand pages and to the left on left-hand pages; this is a right-hand page) is Hebrew and to the inside is Greek of the same text. The Old Testament Greek text was edited from the Septuagint and the New Testament was compiled from older Greek texts. Above each Greek word is a translation in Latin. Since Hebrew is written from right to left, including an interlinear translation with the Hebrew would not have been practical, and so the editors placed a tiny letter of the Roman alphabet above the beginning (to the right) of each Hebrew word and then put the corresponding Roman letter next to the Latin translation in the middle column. “It sounds complicated, but in practice it is extremely easy to use. Even without knowing a word of Hebrew, one can compare the Hebrew text,” said Christopher de Hamel in The Book: A History of The Bible.
The outer margin contains roots of Hebrew words in the text. The two translations at the bottom of the page are included only in the Pentateuch: the Targum of Onkelos, an Aramaic version written in Hebrew characters, and a literal Latin translation.