For Calendars, the best practice is to go to your Models’ Advanced properties and set “Load Model data on Page Load” to FALSE (unchecked). This is because the Calendar component automatically queries the Model, as needed, after applying appropriate boundary Conditions on the StartDateTime and EndDateTime fields (e.g. so that only Event records for the currently visible Month / Week / Day will be pulled in). What you can do is to Filter on WhatId / WhoId / OwnerId / Subject, etc, to try to just find Event records that are relevant.
