Dogs may watch people eating because they like food, but it is also because they are naturally social animals and are used to living with humans. When dogs see people eating, they will become interested in the food because they hope to get some food as a reward for themselves or to share the human's food. In addition, dogs watching people eat may also be out of a need for socialization and interaction, because dogs are social animals and they want to establish closer connections and interactions with humans.
Watching people eat can also be a form of communication, making dogs feel closer and belonging. However, it is important to note that you should avoid feeding human food when giving your dog food, as some human foods are toxic to dogs and can even cause serious health problems. To keep your dog healthy and happy, it's best to feed your dog food that's suitable for them or specially prepared for dogs.