Can I merge mutiple pdf files into a single pdf and save the output as CSV ?

Yes, but you don't need to merge the PDF forms, you just have to merge data an to export.

In Acrobat Pro use : Prepare form : More (menu) : Merge Data Files into Spreadsheet

@mhR_5519 Yes, you can merge merge multiple pdf files into a single pdf. Can you save it as a CSV file? No, but, you could save as or export as an Excel spreadsheet. But, if you use an online tool, you could convert from PDF to a CSV file. https://convertio.co/pdf-csv