Bundle of papers (6)
(Other definitions for packet that I've seen before include "Sachet" , "Paper or cardboard container" , "Mailboat; item of mail" , "Old boat" , "An awful lot of money" .)
'bundle of papers' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for sheaf that I've seen before include "Bundle, as of reeds for thatching" , "Collection of papers" , "set of papers" , "Reaper's bundle" , "Tied bundle (of corn)" .)