Hi Nahid,
Do you mean that you want to view other user's shared calendar (or the SharePoint calendar) via iPad?
Currently, ActiveSync can only sync calendars owned by user to mobile device, it means that there is not available to view the shared calendar on ActiveSync client (such as iPad).
In the same way, there is not available to view the SharePoint calendar on ActiveSync client. As a workaround, we can only use a browser from mobile devices to access a SharePoint calendar. I am sorry for the inconvenience to you.
Thanks,
Bourne Zhang