After I finish eating my stomach start to blow up what is that?

Gastric emptying. The stomach distends when you eat to increase capacity (=receptive relaxation), then grinds the food to small particles to ease digestion in the intestine. Stomach emptying slows normally in response to a diet high in fats or with big meals. Delays in stomach emptying may result in abdominal distension, as with diabetes, hormone problems, partial blockages, ulcers, etc. Get checked if concerned.
Gastroparesis. This may be due to delayed gastric emptying. This is associated with diabetes and other metabolic conditions. If your condition continues, you should see a doctor.