O! Eric tries assembling desk (10)
I believe the answer is:
escritoire
'desk' is the definition.
(I've seen this before)
'o eric tries assembling' is the wordplay.
'assembling' indicates an anagram.
'o'+'eric'+'tries'='oerictries'
'oerictries' with letters rearranged gives 'ESCRITOIRE'.
(Other definitions for escritoire that I've seen before include "Writing desk" , "Furniture item" , "Support for author" .)