servilleta
napkin
serve
to serve
+
-eta
diminutive suffix
Servilleta means napkin and can be thought of as a small thing related to serve0 (to serve0), with -eta1 indicating it's a small item1.
noun
- napkinA small piece of cloth or paper used at the table for wiping the mouth and fingers during mealsPor favor, pásame una servilleta. // Please pass me a napkin.