User Configuration > Administrative Templates > Microsoft Office 2016 > Contact Card > Contact Tab
User
HKCU\software\policies\microsoft\office\16.0\common\contactcard
This policy setting enables you to remove the Calendar line on the Contact Tab, which is on the Contact Card. If you enable this policy setting, you can remove the Calendar line. If you disable or do not configure this policy setting, the Calendar line appears on the Contact Tab.