Hi,
The number of products doesn't mean anything regarding the size of the database.
You can have a database of 20MB with tens of thousands of products.
And you can have a database of 2GB with 10 products.
It depends what extension you have, how you configured them, how much traffic is on the website, etc.
For example, the database of our website is close to 1000 MB and there are only 30/40 products. Most of the space is taken by the forum in our case.
In any case 20MB is not that much for a Joomla website database. So I wouldn't worry.