Remember that the total chain is tablet <> cable <> charger.
The tablet requests the charger what it can deliver (5V, 9V, 12V, etc); both tablet and charger can request the (intelligent) cable what it can support (1A, 3A, 5A, etc); thereafter the tablet makes its calculated request for required charging. That can be less than expected.
For this purpose I acquired such an intelligent USB
load cable. When the cable is not intelligent or not genuine the max load is autogamically limited to 1A.