Understanding subgrid buttons

CRM2013's subgrid behavior is a little different from the behaviour of CRM2011. This can cause some confusion, if you don't know the reason for this behaviour. There are two behaviours that I know the reason for

1.) You click the "+" button in the subgrid, and a new popup window appears to create a new record.  This means that the parent entity lookup is a mandatory field on the child entity.

2.) You click the "+" button in the subgrid and an inline lookup appears. This means the parent entity is NOT a mandatory field in the child entity.

Today I noticed a third behaviour for which I didn't know the reason for. The table button does not appear next to the "+", for the entitlements subgrid, but does appear for the Contacts subgrid in the Account form. Clicking the table button takes you to the associated view.

When the child entity is not a side navigation item, this behaviour is triggered.

Here we can see that Entitlement relationship does not appear in the left hand side navigation on the Account form, hence the Entitlement subgrid does not contain the table button for the associated view.