You are assuming that the Q10 has speed dialing similar to older devices.
Like you can assign a letter to a number and press and hold that letter.
Speed dialing in BB 10 doesn't work that way. Add a number to your speed dial list - How To - BlackBerry Q10 Smartphone - 10.1
You can use those keys to type with. That's about it.
P.S. - In my opinion, speed dialing is unusually weak in BB 10.