The Mnemonic Bookmark
Having trouble keeping these works of literature in your head? Try sketching the plot in a brief phrase-outline, act by act, keeping track of the "network" or "ensemble" of characters as they shift their positions. You can track plots and subplots the same way. Look for ways the plot elements relate to each other, perhaps as echoes (going in the same direction, repeating the same themes) or as mirrors (going in opposite directions or expressing opposite themes).
You probably will discover that you have trouble remembering characters' names, though you can tell me what they did with commendable accuracy. This is because natural human memory converts complex narrative to a prose summary, dropping out difficult to remember terms (Italian names?) and reducing the actions to the minimum. English majors need artificial memory aids to provide them with a bigger trove of remembered text.
Take a tip from a confirmed "dysnomic" (trouble remembering proper nouns, especially people's names). Make a 3x5 card or strip of paper into a "bookmark" for the Norton as you read, and use it to list characters' names and key attributes. If you start doing that for each assignment, you can add to your "bookmark" as you study (key words and phrases associated with characters (e.g., "Now gods, stand up for bastards!"=Edmund), relations to characters or situations in other works (e.g., Mosca/Oswald/Courtier), and issues that are likely to show up in the final exam essay topics (greed perennial or peculiar to modernity?; literacy and power for men and differences for women [Wife of Bath, Margery Kempe, Lady Pol]). If you do that a little bit each time you study, you will have better retention for the quizzes, and you also will have a readymade aid for studying for the final exam. Students who have tried this "note card" method report dramatically improved coherence in their memory of the readings. You can and should still take notes in the book's margins, but use the card to extract the bits you want to remember even if you forget everything else--like characters' names. Then you won't have those Homer Simpson "D'oh!" moments in the quizzes.