What info/data is sent to the CPU when pressing keypad numbers
When you press any key, a scancode is sent to the motherboard.
When you release that key, a different scancode is sent.
with num lock off?
The state of num-lock has no effect on what is sent from keyboard to motherboard. It only affects how your operating system interprets the meaning of the scancodes.
Some keyboards have some local intelligence built in, these may not send scancodes under some circumstances (e.g. built-in calculator, toggle games modes, etc).
Most basic keyboards do not. For example, you may have noticed that when you press (and release) Num Lock a LED indicator light goes on or off. The state of the LED is not controlled internally by the keyboard itself. This is why it is a useful test of your keyboard's connection to the motherboard and of the healthiness of your operating system.
while num-lock is disabled ... the cursor moves from ... field to other fields.
That's because the numeric keypad is normally labelled like this.
If the OS thinks num-lock is on, the scancode from releasing 6 is interpreted as a digit
6. If the OS thinks numlock is off, the same scancode, from releasing 6, is interpreted as
⇨ right-arrow (move cursor right)
So num-lock† acts like a kind of shift-lock for the numeric keypad. It causes the function of the numeric keypad to toggle between numbers and cursor-movement. It is not intended as a way of completely disabling the numeric pad.
†More accurately, the OS chooses to interpret the scancode sent by releasing Num-Lock as switching to an alternative set of interpretations of the scancodes sent when numeric keypad keys are released.