This sounds like a great idea for a party! I would probably add tortilla chips, salsa, and cheese dip to the menu. You can even put the bowl of dip in a sombrero.
Maybe there is a Mexican craft that they could make.
As for games, here are a couple:
WORD FIND
Take a Mexican, Fiesta or Cinco de Mayo related word such as guacamole or festival. Challenge the children to find as many little words as they can.
Example: Guacamole
Words: came, come, me, am, game, gem, cue, male, meal, mole, mule, ace, camel, coal, lag, camel, go, goal, coal, etc.
ESTIMATION: HOW MANY BEANS IN THE JAR?
Need: Large glass jar filled with a variety of beans
Small pieces of paper
Sombrero (if available)
Pencil
1. Have children write their name and guess on a small piece of paper.
2. Have them place the number of beans guess in a container or sombrero.
3. The correct of closest guess is the winner