My experience with Adobe (and Adobe Acrobat) is that you can convert many files types (such as Word and Excel) into pdf readily. (That may have been one of the points of the pdf – it makes it difficult to tamper with the original document, like making a copy on a Xerox machine. And anyone can open the document up to read it.)
With Adobe (and Acrobat), you can convert a pdf document to a .txt or .rtf file that can be opened in Word, but all of the formatting (returns and page breaks) I believe are lost.
You could attempt to convert a table to .txt or .rtf and then open that in Excel, but all of the formatting (column width, formulas) is gone. I think you will also end up with a spreadsheet 1 row high and many columns wide, each cell occupied by a single word or single number and blanks (in the original) are lost. Now you could select and move the cells around to reconstruct the table (excluding the formulas). If it were just numbers, it could be worth it. Text however, will probably have been parceled with a word in each cell.
Joe