Confusion regarding USB and charging is widespread, commonly misunderstood even among those that otherwise feel comfortable with 'tech'.

I have yet to see a multi port USB charger that even claims to be able to deliver maximum charging power to all outlets at the same time, let alone a charger that actually does so. As in the example linked above, the maximum power output of the charger is less than the maximum per port output, multiplied by the number of ports.

2.4 amps per port times 5 volts (all commonly found USB is 5 volts, excluding the very recent USB-C and special cases) equals 12 watts per port. 12 * 6 ports is 72 watts, which is significantly more than the '50 watt' product description.

When you plug in a recent model iPad or an iPhone 6/6+ the device will sense the claimed maximum power output of the charger (via signals on the USB port data pins), then attempt to draw the full 10 or 12 watts that the device can absorb. If the charger output voltage stays stable at 5.00 volts or slightly above then the device will draw the maximum allowed power and recharge in the quickest possible time frame.

If the charger cannot maintain the necessary precise 5.00 volts when the device ratchets up the requested charging current then the device will back down the power demand until the charger can again provide a stable charging voltage. You will not see any indication on the Apple device regarding which charging rate is happening, as long as the rate is at or above the minimum.

When the minimum power is not available, (for example) a full sized iPad needs more than 2.5 watts to simply run with the LCD display lit up. If the iPad is plugged into a USB power source that can only deliver the basic 2.5 watts then the iPad will show the 'Not Charging' message where the lightning bolt icon would normally appear (top right corner). When the iPad is sleeping (LCD screen is dark) it will indeed be charging, just very slowly.

How this particular charger will cope with multiple devices that in aggregate demand more than the rated 50 watts, I cannot predict. How your connected devices respond when the charger begins to dial back the available power per per port will depend on the particular devices, and the order in which they are connected. The first three or four devices I would expect to receive full charging power, beyond that would depend on the device mix. And their individual states of charge.

* The 10 Amps spec is related to the 50 watts maximum for the charger overall.
5 volts times 10 amps equals 50 watts.