Your calculated fields should be done either in a Query or directly on your Form/Report. Not in the table.

I think, I didn't explain myself clearly: I don't want to calculate it in a table, I want to store formula in table and use it in a query.

I generally recommend that you DON'T store the value in the table if it's something that you can easily calculate in a query. However, if you do want to store it in the table, you can use a Calculated Table Field (which I recommend against) or an AfterUpdate in a form field to perform the calculation.

Why is the formula needed in the Table?
Are you wanting a table with different formulas and you are going to lookup up a formula and use it?

Could you give and example of what and when you'd use it?

This is exactly why I want it, Alex.
I trying to create 'production sheet', basically list of steps required to make specific part.
Almost every step need more information added for specific part (like dimensions, material etc.).