You could add in a new data table based on your first table, and add in a 'Transformation' on that data table creation of 'Unpivot' and you can perhaps transform your table back to a similar original state. But I imagine that pivot then unpivot could potentially cause some data structure issues (ie it might not always be exactly as it started).
But if you need to have both versions in your analysis I would suggest you have 2 tables:
Insert table from data source (no transformation) - Example Name: MyDataTable
Insert table from MyDataTable - Add 'Pivot' Transformation - Example Name: MyDataTable (Pivoted)