Seein gother attached files apart from just PDFs

While papers are almost always in PDF format, accompanying information/data often is not. I can attach additional non-PDF files to a reference, but unless I specifically open the refence and scroll down, I am not aware of these additional non-PDF files. Instead of only showing pdfs in preview, there should be an additional tab or tabs to preview WORD and EXCEL files assocaited with a reference at the very least.