Bill and Grant touring the French plateau (9)
I believe the answer is:
tableland
'plateau' is the definition.
(synonyms)
'bill and grant touring the french' is the wordplay.
'bill' becomes 'tab' (tab is a kind of bill).
'and' is a charade indicator (letters next to each other).
'grant' becomes 'land' (land grant is a kind of grant).
'touring' is an insertion indicator (touring can mean going round).
'the french' becomes 'le' ('the' in French).
'tab'+'land'='tabland'
'tabland' placed around 'le' is 'TABLELAND'.
(Other definitions for tableland that I've seen before include "Broad high plateau" , "Elevated area" .)