What was the woman doing before she went home?

M: Did you finish typing that report?
W: Yes, I did, but I worked late.
M: But it must be a long report, I guess.
W: Exactly. Twenty pages. I spent three hours on it.
M: By the way, what time did you go home?
W: I left the office at nine o’clock. I got home at ten.
M: What did you have for dinner?
W: I sent out for a sandwich and ate at my desk.