Computer Configuration > Administrative Templates > Google Chrome
Both
HKLM\Software\Policies\Google\Chrome
This policy controls the visibility of cards on the New Tab Page. Cards surface entry points to launch common user journeys based on the user's browsing behavior. If the policy is set to Enabled, the New Tab Page will show cards if content is available. If the policy is set to Disabled, the New Tab Page won't show cards. If the policy is not set, the user can control the card visibility. The default is visible.