Change table, by the sound of it (5)
I believe the answer is:
alter
'change' is the definition.
('alter' can be a synonym of 'change')
'table by the sound of it' is the wordplay.
'table' becomes 'altar' (altar is a kind of table).
'by the sound of it' indicates a 'sounds like' (homophone) clue.
'altar' sounds like 'ALTER'.
(Other definitions for alter that I've seen before include "Adapt" , "Change or adjust" , "Metamorphose" , "Change, modify" , "reform" .)