Go to carry a salver (4)
I believe the answer is:
tray
'salver' is the definition.
(I've seen this before)
'go to carry a' is the wordplay.
'go' becomes 'try' (I've seen this before).
'to carry' is an insertion indicator.
'try' going around 'a' is 'TRAY'.
(Other definitions for tray that I've seen before include "platter" , "Informal meal" , "Flat carrier" , "Flat utensil for carrying food" , "Item used for carrying food and drink" .)