pick your brain on excel spreadsheet creation?

So I Work in Desktop Support and have excel spreadsheets that are generated by Cisco switches which contain usage reports.
I look at these to determine if a port hasn't been used in a long time and it can be re-allocated (resulting from an office move, etc.)

I have been trying to find a way to look at these excel spreadsheets quickly and determine whats been used. Most of the time what I have done is create pivot tables and really jury rig a way to do it albeit improper. This is time consuming for each individual report and can be a nuisance.

This is an example of the data in the spreadsheet:

Device Name Interface Timestamp Severity Mnemonic Description
NH1SW018 10.5.2.5 Dec 12 2007 06:33:13 5 UPDOWN FastEthernet0/1, changed state to down
NH1SW018 10.5.2.5 Dec 12 2007 06:32:40 3 UPDOWN FastEthernet0/1, changed state to up
NH1SW018 10.5.2.5 Dec 12 2007 06:32:42 5 UPDOWN FastEthernet0/1, changed state to up
NH1SW018 10.5.2.5 Dec 12 2007 06:33:17 5 UPDOWN FastEthernet0/1, changed state to up
NH1SW018 10.5.2.5 Dec 11 2007 15:09:36 5 UPDOWN FastEthernet0/16, changed state to down
NH1SW018 10.5.2.5 Dec 11 2007 15:09:56 5 UPDOWN FastEthernet0/16, changed state to down
NH1SW018 10.5.2.5 Dec 11 2007 15:09:41 5 UPDOWN FastEthernet0/16, changed state to up
NH1SW018 10.5.2.5 Dec 11 2007 15:10:01 5 UPDOWN FastEthernet0/16, changed state to up
NH1SW018 10.5.2.5 Nov 29 2007 21:57:12 5 UPDOWN FastEthernet0/19, changed state to down

Device name being the switch name, description showing the port 0/1 would be port 1 on switch 0 of the chain. Some switch names have multiple switches grouped.
I would like to think of a clever worksheet I can either A: paste this data into a sub sheet of or B: reference all the data from a sheet named whatever I choose to name it and saved in a certain location. I can just call the file D:\reports\switchxyz.xls for example.

The problem is some of the spreadsheets are longer than others because of obvious activity differences. I need to reference all the data but if I try to reference a generic cell set I get Null#.

Can someone think of a crafty way to pull data from there and present it into a chart which can be used as a template for multiple switches on a monthly basis?

I was hoping someone else might have a few ideas. Thanks!