You already have the maximum VRam set, the Intel graphics memory is 64 Mb, the rest of the memory is taken from Ram or VRam which you have given as the total available graphics memory - 1696MB.
You would have to check if there is an option to increase in the BIOS, I'm not sure if it's the maximum limit or not, maybe adding RAM would help but I'm not sure to wait for someone else to speak.