I doubt this very much
A scale that can weigh up to say 500g has a load cell of only that capacity, if you place something on it and tare it, it will not give you "more" room to weigh stuff on, cause you are already at the load cells cap, it might show 0 after you tare it, but I guarantee it wont weigh much more on it, and you also stand the chance to damage the scales load cell.
Just for reference, I work in a Laboratory
A scale that can weigh up to say 500g has a load cell of only that capacity, if you place something on it and tare it, it will not give you "more" room to weigh stuff on, cause you are already at the load cells cap, it might show 0 after you tare it, but I guarantee it wont weigh much more on it, and you also stand the chance to damage the scales load cell.
Just for reference, I work in a Laboratory