Quarrel involving a restaurant's initial list of charges (6)
I believe the answer is:
tariff
'list of charges' is the definition.
(I've seen this before)
'quarrel involving a restaurant's initial' is the wordplay.
'quarrel' becomes 'tiff' (tiff is a kind of quarrel**).
'involving' means one lot of letters goes inside another.
'initial' says to take the initial letters.
The first letter of 'restaurants' is 'r'.
'a'+'r'='ar'
'tiff' going around 'ar' is 'TARIFF'.
(Other definitions for tariff that I've seen before include "List of fixed charges as in hotels" , "Rate" , "Table of (hotel) charges" , "Fees schedule" , "Tax or duty to be paid on some imports or exports" .)