Save old data and append to live table

Hi all, 

I have a data source that contains only what a customer is currently entitled to. It changes every week. I want to be able to do month-over-month trend analysis on things like number of customers. To do this, I want to save the old data to my current live table, with a column showing the data refresh data. How would I do this? (I have a Premium workspace)

My ideal table would contain April 2020 data, and then when May 2020 comes around, have both April 2020 and May 2020 data in the table with a refresh date indicating that the May 2020 data is current and the April 2020 data is archive data.

Thanks!