Captivating orator to read out letters, having file of documents (11)
I believe the answer is:
spellbinder
'captivating orator' is the definition.
(someone spellbinding an audience)
'read out letters having file of documents' is the wordplay.
'read out letters' becomes 'spell' (spelling a word).
'having' means one lot of letters go next to another.
'file of documents' becomes 'binder' (binder can mean a folder of documents).
'spell'+'binder'='SPELLBINDER'
'to' is the link.
(Other definitions for spellbinder that I've seen before include "Enthralling speaker" , "Gifted orator" , "A fascinating one" .)