τοί is often used in statements of a general truth and in expressions of personal conviction (sometimes with a tone of hesitation); in remarks of a confidential nature; to introduce an explanation; and in general where the special attention of the person addressed is desired. τοί often gives an easy and familiar tone to a reply. Thus,
τῶν τοι ματαίων ἀνδράσιν φρονημάτων ἡ γλῶσσ' ἀληθὴς γίγνεται κατήγορος
a. τοί may emphasize particular words, as ἐγώ τοι, ἐμοί τοι, σέ τοι; and other words not pronouns.
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].