Small businesses often use out using things like excel to manage different parts of their compliance systems.
It is not unusual for training matrices to be one example of where excel is used. But here's the thing, excel is simply brilliant for working with numbers. It is not so good for trying to manage compliance tasks. Unless you have somebody routinely logging in, excel won't tell you who's certificates have nearly expired (or worse, what's overdue).
It is possible to apply some clever conditional formatting to an excel spreadsheet to give you a visual indication of the status of certificates when you log in, which can help a bit, but it's still no substitute for a system that automatically calculates due dates; sends out reminders to all the relevant people (from training managers to the trainees, if that's what you want) and stores the certificates against the individual employees.