One big book on record as a typical example (7)
I believe the answer is:
epitome
'a typical example' is the definition.
(I've seen this before)
'one big book on record' is the wordplay.
'one' becomes 'i' (Roman numeral).
'big book' becomes 'tome' (term for a large or heavy book).
'on' is a charade indicator (letters next to each other).
'record' becomes 'EP' (abbreviation for extended play record).
'i'+'tome'='itome'
'itome' put after 'ep' is 'EPITOME'.
'as' acts as a link.
(Other definitions for epitome that I've seen before include "Digest" , "Typical example, prototype" , "classic example" , "Exemplar - embodiment" , "Summary of a written work" .)