An Attic Paper-boy? Probably, 'one who brings joy'.
The inscription known as IG I³
1281 (= IG I² 1051) reads ΧΑΡΤΟ and no more. Since it is from Attica and dated to c. 450 BCE, the <Ο> could represent or <ου> or <ω>. If this is a noun, the first and the last can be ruled out on morphological grounds (I presume that the iota of the dative singular would have been written at this time).
Kurtz-Boardman, p. 123, fig. 22a
LGPN takes this as the genitive χάρτου of a name Χάρτης, as in the Index to IG I³ (cf., perh., papyrus(-roll) χάρτης m., Latin charta f.) and, as of today, knows only this instance. An alternative is suggested: Χάρτος (as in the Index to IG Supp. and IG I²); cf. χαρτός.
There are several names in χαρ- [χαίρω].
See Bechtel, pp. 469-470. See also Bechtel, pp. 468-469, for names related to χαρμή.