Now I'm using EF 6 database first and i need to add new table

Question

I'm using EF 6 database first. Now i need to add new table to my project. Can i add this table into .edmx Main model and from it update my DB but have Mapping error? Or i need create new empty EF .edmx model and from it update DB instead of an Main model. And then update Main model using Update Model From Database option. Thnx.