You know, I've never actually counted them although we can estimate them from pictures on the web
M8310 - 53 chips (http://www.classiccmp.org/hp/My%20PDP-8%20Cards/M8310.jpg)
M8300 - 64 chips (http://www.classiccmp.org/hp/My%20PDP-8%20Cards/M8300.jpg)
So 117 chips, so not quite 10X but the nibbler does have an LCD display and if you add the PDP-8/e programmer console to the mix you're probably close to 170 chips. So great estimate!
I guess, the PDP has at least 10 times more (equivalent) chips inside.