User1 can always access table1, since user1 is the owner.

User1 can always access table1 through view2, since user1 is the owner of the underlying table. This is true even if user2 does not grant privilege on view2 to user1.

User2 can access table1 directly or through view2 if user1 grants privilege on table1 to user2.

User3 can access table1 if user1 grants privilege on table1 to user3.

User3 can access table1 through view2 if user1 grants privilege on table1 to user2 with grant option and user2 grants privilege on view2 to user3.