I believe you can insert an external link (URL) in revit files. Copy-paste entire files directly into Revit would mean embedding that information into the revit file. Meaning the revit file size would increase dramatically affecting directly the speed and behaviour of the revit file. You can mimic excel tables in revit by using schedules. I've seen some lynda.com tutorials on that. Quite ingenious, involves creating some text-type parameters and the parameter values are exactly the text you need. For word texts, copy the text from word and insert it in a keynote.
I would certainly not recommend inserting autocad elements into revit, since revit will treat them as individual linework elements (CAD elements), not BIM elements, again slowing down performance dramatically.