Hi Jennifer!
Thank you for bringing your question to the Disney Parks Moms Panel. I've been a Disney Parks fan for as long as I can remember, but I still remember my first trip as a momma with my own mouseketeer and I had this exact same question!
While tiny tots under the age of three do not need a
ticket for entry into
The Happiest Place on Earth, they should be included in your
dining reservation headcount. The reservation headcount is used to account for table space required to account for your party, not necessarily meals on the receipt. If you make a reservation without your two year old, when you get to the restaurant they'll certainly accommodate your group, but you may experience a delay based on tables they were planning for. To keep your day running as smooth as possible to give you maximum time to explore Disneyland Resort, you'll want to make sure to include all Mickey fans when making dining reservations, regardless of age.
I hope this helps in planning for your upcoming visit! Please come back and see us real soon if any other questions arise.
-Lindsey