Your dog is probably just getting territorial over food.
This is one reason us humans should never give into our dogs when they're begging for our food.
If you give into your dog when they sit and stare at you begging you while you eat and you give them food then they know that if they just beg or even get aggressive or even just bark at you for the food then you'll give in and they'll get their food.
Us humans should eat our food first and not give any of our food to the dogs. After you eat and put your plate away you can then feed your dog their dog food.
Don't give them what's left over on your plate either. Throw the leftover food into the trash and then give them their dog food.