To determine what the speaker is thinking about in the stanza, we would need more context about the specific poem or piece of literature you're referring to. However, based on the mention of "a woman named Lenore," it suggests a connection to themes of loss and longing, particularly as Lenore is often associated with melancholy or idealized love in poetry, most famously in Edgar Allan Poe's works.
If the speaker is reflecting on "his uncomfortable room," it might indicate feelings of isolation, discomfort, or an introspective state. “His guilty conscience” suggests he may be grappling with feelings of remorse or regret, and “a terribly sad book” implies he might be immersed in themes of sorrow or reflection.
If I had to choose based on these options and typical literary themes, I would lean towards "a woman named Lenore" as a strong possibility, especially in connection with themes of love and loss. However, context is crucial for an accurate interpretation.