General responsibilities are listed below:

Answering phones, taking messages and setting up conference calls.
Receiving and responding to correspondence and all public enquiries.
Writing up request lists for clients.
Managing meeting room diary, greeting clients.
Keeping MD tour planner up to date.
Booking couriers and travel for staff and clients.
Keeping the office running smoothly day to day; cupboards and fruit bowl stocked , printers & faxes stocked & working, white goods working etc.
Keeping the company in line with health and safety requirements; fire extinguishers, emergency exits, intruder and fire alarms etc. maintained.

These responsibilities are constant throughout but there is a lot of room to take on more, it's one of those things that when the office is busy and has a lot going on then you'll be busier and when we're quiet you will have quieter days too, as with any media agency.

Checking box office numbers on posters
Office Filing
Collating information for tours
Booking client trains
Running for TV and Live Events

And generally assisting all staff members.