How to process and write a new field to the database (Magento)?

Question

Magento

I had no business with Magento (based on the question, I think it's clear).
Conventionally, there is a feedback module, in which the fields:
-text
-name It is
necessary to add the rating (rating) field - respectively, to the database and then display it.
The field is added to the template.
Further stupor.
As close as possible (with a record to the database) what I found in the controller, after processing the fields:
/* processing here */
$model->save();
And redirect back.
To create a table, in the config (in config.xml), as I understand it, there should be something like:

<entities>
  <reviews>
     <table>user_reviews</table>
  </reviews>
</entities>

There is no such. But the feedback is recorded and displayed.
I didn’t find the table in the database either, only in some kind of entity, category or something like that with the prefix.
Googling was faster than writing a question, I already tried it.
Reading is not a problem, I will be grateful for links in the right direction, and even more for explanations =)