Within our cemeteries, it is common to find among different symbols objects that may reflect either the profession of the buried person, or act as a reference to their affiliations or membership (i.e. Freemasonry). They may also represent their hobbies, leisure or fields of interest.
In that sense, scales would generally represent the law, and therefore be associated with lawyers or someone within the legal profession. It shouldn’t be interpreted simply as “divine justice”.
Scales can be found held by a sculpted woman (Lady Justice), the image of a blindfolded woman wearing flowing robes that looks like a Greek toga and holding in her hands the scales of justice and sometimes a sword.
Such image is derived from Justia, the Roman Goddess of Justice.