Do you have the rest of the datasheet?
I looks like it might be ks0108 display.
I would bet the data sheet is wrong - which is not uncommon.
typically a 128x64 glcd is composed of two 64x64 sections so there is chip select
for each section. There would be no need for 3 chip selects on a 128x64 ks0108 module.
Also, the backlight usually has its own power pins.
If you look at this pinout, there is no pin for the cathode of the backlight.
I'm guessing that the Vee signal is actually on pin 18 (which is where most ks0108 displays have it)
and then pin 19 is the backlight anode.
Since hooking things up incorrectly can smoke the glcd or the arduino, here is what I'd do.
First make sure you have the correct datasheet.
Do you see the part number that is on the back of you glcd somewhere on the datasheet?
If not, go look for the correct datasheet.
Even if it does match the datasheet you have, I'd still recommend going
and looking for another datasheet as this one looks like it has errors on it.
Once you find the correct datasheet hook up only
power and ground to the glcd power and ground pins
(pins 1 & 2 in this image)
Then check the glcd pins for the Vee voltage. It will be around -8 to -10 volts.
Most ks0108 displays have Vee on pin 18.
As you check this, be very careful not to short any of the signals as can damage
the glcd.
When you see the negative voltage you can verify that you have the correct pin for Vee.
But most importantly make sure the datasheet is for you display as even
the main power pins are not in the same location or order on different modules.
--- bill