“Yesterday I WORKED in my office for eight hours till 9pm.” is correct, cause you are not talking about a particular action that happened or was happening yesterday(while you were working), so you don’t need “was working”(continuous). “I was completely absorbed in my favorite book on my way to work and back home “. You don’t need “to” with “home”. I hope it helps Borislav, :)

Yesterday, I worked in my office for eight hours till 9 PM. -> Place before time, unless you want to stress the time (like yesterday) -> You would not use the continuous form here, because the continuous is used for emphasizing that something was in progress: Yesterday, I was working in my office, when the robber came in. I was completely absorbed in my favorite book on my way to work and back home. Here you don't need the preposition. You would need it for sentences like: Back to school Back to work Home is the odd man out here