SCHEDULE FOR DOCTORS ON CALL

I am trying to make a data base in order to plan the schedule of the activities and on call duties of the doctors in my department. I would like to make multiple choices of activies for every day and each activity can be done from 1 or more doctors. That means that my main table will be the calendar. The doctors and the activities have to be connected to the calendar. I tried but unfortunately when I am connecting the doctors and the activities, the fields they do not appear in the table view of the data base. How can I solve this problem?