Let's just step back one and ask you this. Why do you need to dig into the details of IRQs?
The reason I am asking that question is...when the menu "PnP/PCI configuration" is selected there are
[*]PnP OS: yes/no[*]Second menu is something like controlled by [Disabled/Enabled][*]IRQ resources: [Auto][/list=a]
The last one is ideally set to auto, unless you want to assign everything manually. You need to refer to the table (in the manual) only when manual adjustments are desired. with the now-a-days devices [AUTO] should be ok.
I don't know if I am giving you some clear picture or messing up your mind, but instead of digging deep into the manual (IRQ assignments) I would do [AUTO]. I will look into the manual and see if I can explain any clearer than it reads.
Cheers !!!!