A query field does not save anything to database. Its purpose is to display the results of your SQL and nothing more. If you need to push the value to the database you'll need something like CB Auto Actions to do that. Why do you need the query result saved in the database?

Another table from where? For what? Is your other usage not able to take those 2 existing values and divide them as you're doing in query field? At any rate you won't be able to store them without something to push the values to the database and for that you'll need CB Auto Actions, which typically just pushes the query fields value to another field as its value (e.g. set a text field to the result of a query field using a field auto action).

Another table from fabrik.

Best I can suggest is see if Fabrik can do the math for you if it has some sort of SQL fieldtype. Aside from that you'd need CB Auto Actions to push the query result to a different table. I suppose you could have a query select fieldtype and have only 1 dropdown option available (the results of your query), but that's a bit strange to have a dropdown with a single value.

I thought that CB Query stored data also in the CB table.

It can with a query select fieldtype, but that just uses your custom SQL to determine the dropdown options available for selection; it does not display the results of a custom query. Beyond that am unsure where you got that impression as the first sentence of the plugins description is quite clear with "Lets you grab data using a database query and display results as a CB field.".