Extra diaper and diaper wipes
Clean dry washcloth, to wash them up after the meal
A big if they will use it or a clean shirt to change into if needed
Their own eating utensils and drinking cup
Bring one of their favorite healthy snacks in case they will not eat the food at the restaurant
Pack a few small quiet toys to play with at the table if your child should finish eating and get restless before your done eating.
Once at the restaurant, choose seating where fewer people are dining so your child is less likely to disturb other diners and there is less distraction for your little one.
Use the high chairs and booster seats available at the restaurant to secure them safely and to prevent them from being able to move about freely.
Keep in mind that small children get bored quickly and patience is not something they have not learned at this age yet. Your child may not sit well thru appetizers or waiting for meals that take some time to prepare. Buffet type restaurants are good choices for dining out with small children. Your family can be seated quickly and begin enjoying the food quickly. Also, the kids love the variety which is helpful for picky eaters.
Be patient with your toddler. If your child gets a little out of sorts, keep in mind their behavior is typical for this age. They will learn appropriate behaviors for such activities over time by example and experience.