Have a snooze before diminutive ruler calls for items from the dining room (6-5)

'have a snooze before diminutive ruler' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.

'calls for items from the dining room' is the wordplay.
'calls' becomes 'rings' ('ring' can be a synonym of 'call').
'for' is a charade indicator (letters next to each other) (I've seen this in other clues).
'items from the dining room' becomes 'napkin' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'rings' after 'napkin' is 'NAPKIN-RINGS'.

Can you help me to learn more?