This is the 16481st most frequent Russian word.
салфеткой
"Салфеткой" means "napkin" (instrumental case).
In this sentence, 'салфеткой' is used as an instrumental noun, referring to the object used to perform the action of wiping the table.
Я вытер стол салфеткой.
I wiped the table with a napkin.
Here, 'салфетка' is used as a noun in its nominative case, describing an item being present on the table.
На столе лежала салфетка с узором.
A patterned napkin was lying on the table.
In this example, 'салфетку' is the noun in its accusative case, showing that it is the direct object of the action 'pass me.'