An Office Assistant is responsible for keeping the office supplied and organized. This involves lots of small duties, like typing and taking notes during meetings.
Office Assistants are responsible for things like:
Overseeing clerical tasks, such as sorting and sending mail
Keeping an inventory of office supplies and ordering new materials as needed
Maintaining digital files
Welcoming visitors to your office
Answering phone calls
Taking and delivering messages
Scheduling meetings and sending meeting invites to attendees
Following up on candidates for the recruiters.