It sounds like you have to discuss the book as you read them. They expect a lot of work for two books.
I'm assuming they expect you to finish the books in three settings (don't forget to record the date of each log), so you don't have to finish it all at once. Try reading the books in three equal segments, or even if you finish the book in one day, do the discussion in three different entries.
I would probably set it out like this:
Date:
Page: (page you're doing the entry/have read up to)
Here you would discuss the characters, plot, etc., etc. Whether you do that with subheadings or as an essay with each paragraph corresponding to one point would be up to you.
Don't forget to mention how the characters, plots, etc., etc have changed an evolved as you progress through the book.