How are you all using Requirements tab? Who enters requirements BA or QA?

At present our BA team is writing requirements in word document and sometimes they can be 80 to 100 pages with screenshots. Who is responsible to enter those requirement in QAComplete BA or QA in your organization? Or BA's don't create a document and directly utilizing a requirement tab to enter requirements. I am trying to find a best practice, to reduce efforts in our organization. Also, is it a  good tool for BA to write requirements or they writing in different tools and then migrating those here. Please help and share your process.