Is the dish of Ashura considered an innovation (bid‘ah) on the Day of Ashura, or on the day before or after it? And what is the ruling on indulging oneself on one's birthday by bringing fruits and sweets without holding a party?

If the Ashura meal is accompanied by slapping and striking, then it is a reprehensible innovation that must be avoided. However, if it is not so, and its purpose is to provide abundance, then there is no harm, but the narrations regarding providing abundance on this day are weak. As for providing abundance in food to celebrate a person's birthday, it falls under the category of forbidden celebration and glorification.