Game monarch hosting cool queen's band at dinner (6,4)
I believe the answer is:
napkin ring
'band at dinner' is the definition.
(metal band for holding a napkin)
'game monarch hosting cool queen's' is the wordplay.
I cannot quite understand how this works, but
'game' could be 'p' (I have seen 'French game ' mean 'p' so perhaps 'game' could also mean 'p') and 'p' is found in the answer.
'monarch' could be 'r' (abbreviation for rex, king in Latin) and 'r' is found within the answer.
'cool' could be 'in' ('in' can mean fashionable or cool) and 'in' is found in the answer.
This explanation may well be incorrect...
(Other definitions for napkin ring that I've seen before include "Serviette hoop" , "Serviette holder" .)