We thought about this when we added tables, and while this is indeed useful it’s not in the scope of a note-taking app.
For having formulas we would need to add labeling/numbering of the cols/rows for you to be able to reference them and choose some kind of syntax for the formula of which there is no real standard. The formula would only work in Bear and not in any other editor, nor you’ll be able to see the results in the plain text file.
That said, we want to add more power to tables (sorting for example) and we might add some kind of very basic math support (automatic sum, avg, etc…), but all of this after the 2.0 release 