Rewarding academic, second 'character' from High Table (10)
I believe the answer is:
profitable
'rewarding' is the definition.
(similar in meaning)
'academic second character from high table' is the wordplay.
'academic' becomes 'prof' (short for professor).
'second character from high' becomes 'i' (2nd letter of 'high').
'prof'+'i'+'table'='PROFITABLE'
(Other definitions for profitable that I've seen before include "useful" , "Rewarding" , "offering good returns" , "Money-spinning" , "Cost-effective" .)