Tabular data vs Normal sheets

I have a problem. I have a data set that needs to be imported and then scrubbed using auto filter and fill down. I then use a pivot table to analyize and then auto filter and fill down again.

I understand that Auto Filter and Pivot tables only work with tabular data while fill down only works with normal sheets. Is this right? Is there any way to move back and forth between normal and tabular formats?

How can I address this issue?