The output voltage!
The large adapter can output 4A at 10V while the small one can charge the end device at 4.5V or 5V with up to 4.5A.
The large tablet batteries are usually divided into 2 cells so that they can be charged in parallel (as if you were charging 2 smartphones at the same time --> 10V = 2x 5V). I would definitely go for the smaller one for the Huawei smartphone.