Tablets working on joint destroyer? (10)
I believe the answer is:
battleship
'destroyer?' is the definition.
(thesaurus)
'tablets working on joint' is the wordplay.
'working' is an anagram indicator.
'on' means one lot of letters go next to another.
'joint' becomes 'hip' (part of body).
'tablets' is an anagram of 'battles'.
'battles'+'hip'='BATTLESHIP'
(Other definitions for battleship that I've seen before include "craft for action" , "Vessel of war" , "naval craft" , "Heavy warship" , "Hood, say" .)