I don't think the cable is particularly important. Its the jack that the cable plugs into that makes a difference.
Basically, if the tablet can tell that its plugged into a special (high amp) jack, then the tablet will charge more quickly (at 2A), otherwise the tablet will assume its plugged into a standard USB port and charge at the specification limit (500 mA). The best way to get an adapter that the tablet can identify is to use the official wall adapter. I believe there is no "standard" way of doing this, so different manufacturers may do different things (e.g., using an Apple USB charger may not work).
You should be able to see what your tablet is doing based on the battery icon in the system tray (assuming its similar to the older Galaxy Tab that I have). On my tablet the icon will have a small red "X" if its being charged through a "normal" connection, and should have no such "X" if its being charged through a high-amp connection.
See How much power does a Galaxy Tab 10.1 charger need to supply?
And Do Samsung tablets have the same USB connector as Apple's iPad?
And Why is charging from computer using USB slower than using an outlet?