I come from that kind of world and have to wonder if by choosing an interval then equipment that you're putting the cart before the horse so to speak. I could go on about how it all worked but I don't think it's anything you'd want to consider building.
What I don't get about what you've shown is, don't you have to handle that same piece of paper every week for 2 years? Or are you looking for a form for input, a report for output (the grid you show) and supporting tables so that you can reprint along with the historical data? This would require a fair bit of coding to support that because of your csv approach to the data. In all my years of Access only once have I ever needed to have csv data in one field. If that's your goal I'm not sure that it's the best approach for the job here. Have you considered a work order based approach instead of trying to show multiple frequencies for the same equipment/unit?
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.