Not sure if anyone has suggested it yet but wouldn't this be a perfect app for a smartphone?
Scan the bar codes with the cell to load the items into the sheet then just add the date of purchase (could even add the date of expiration,
Cellphones can now print to most printers so a weekly rescan could update the sheet.
Personally I'm looking for the day my "Smart-fridge "can TELL me it is a "bad idea" to eat that out-of-date by 3 months Yoplait Yogurt.
( never see tose tiny numbers till after the first mouthful when it is too late!
I have seen an egg tray for any fridge that already does that based on scans of he insides of the eggs. Might save a quick trip to the Er.