The Prose Edda takes form at some point in the thirteenth century. The uniform tradition is that it was 'assembled' by the great Snorri Sturluson, but it's unclear at times exactly what parts are due to Snorri as author and for what parts Snorri may have instead served as compiler or editor. The Prose Edda is generally regarded as consisting of four parts:
I. The Prologue, which treats Odin and the other Norse gods as ancient men of heroic capabilities who are descended from the Trojans.
II. Gylfagynning, the 'tricking of Gylfi', in which the Norse stories are expounded to King Gylfi.
III. Skáldskaparmál, 'poetic language', in which Aegir and Bragi discuss various poetic kennings and phrases.
IV. Háttatal, the 'tally of meters', which goes through the various different kinds of traditional Norse verse forms. This section we know for sure (or at least, as 'for sure' as we can get) to be authored by Snorri.
Ironically, the fourth part, which is certainly Snorri's and not just compiled by him, is virtually never found in any English translation, presumably because of the extreme difficulty of translating a technical discussion of metric forms into a very different language. I'll be using the Penguin version, translated by Jesse Byock, which lacks the fourth part as well. It has an appendix giving a brief sample, and I may see if I can find a few other samples, as well.
Title page of the Prose Edda from an eighteenth-century manuscript, depicting various characters and items from the book.