mesilla
nightstand
mesa
table
+
-illa
diminutive suffix
Mesilla means nightstand and can be thought of as a small1 (-illa1) table0 (mesa0).
noun
  1. nightstand
    A small table, typically used as a bedside table or nightstand.
    Puse el libro en la mesilla antes de dormir. // I put the book on the nightstand before going to sleep.