The phrase "This is really a notable growth" is grammatically correct but could be improved for clarity and style. The term "notable growth" typically refers to an increase or improvement that is significant or worthy of attention. The use of "really" is a bit informal and may not add much to the meaning.
To make it clearer or more formal, you might say:
- "This represents significant growth."
- "This is truly notable growth."
- "This is indeed