Is it too little?

Hi mamas! My LO is 7MO.. I started introducing purees and rice cereal when he was 6 months old. My son weighs about 9kg now. He doesn't eat alot. The portion of cereal i give him is about the size of his fist so probably abt 3-4 table spoon. Sometimes he doesnt finish it too. I feed him about 2-3 times in a day but im trying to feed him 3 times a day now. He is fully breastfed. Is it okay if he doesnt eat alot? According to his weight he is in the heavy percentile. I dont want him to gain too much weight either. So isit okay if i slowly gradually increase his solid in take? Will it affect any developments?