my DS who is 4 now, was the same as your little man, he was huge, everyone commented on it and how he must be ready for "real food" from about the age of 3 months!
He was exclusively BF until he was 7 months, then we started Baby led solids (steamed vegies he could hold and chew) but not really forcing the issue.
He showed plenty of interest in food, always eyeing off our food etc, but I just went with what I felt right for me and BFing exclusively was just so easy and hassle free LOL, he was always putting on plenty of weight and even when we did introduce solids he was more interested in boobies

Thats just my experience though.