Table in small scientist's room (4)
I believe the answer is:
slab
'table' is the definition.
(thesaurus)
'small scientist's room' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'scientist's room' becomes 'lab' (laboratory).
's'+'lab'='SLAB'
'in' acts as a link.
(Other definitions for slab that I've seen before include "Large piece (of chocolate, stone, etc)" , "Piece, e.g. of cake" , "Thin flat stone" , "Mortuary table" , "Piece of paving" .)