With respect to the book of Esther and the “canonical” nature thereof amongst first century Jews, one Roman Catholic scholar wrote:
The Mishnah reports that there was discussion near the end of the first century AD about the sacredness of some works:
All of the holy writings defile the hands [are sacred]. Song of Songs and Ecclesiastes defile the hands. Rabbi Judah said, ‘Song of Songs defile the hands, but Ecclesiastes was in dispute.’ . .. But Rabbi Akiba said, ‘God forbid! No one in Israel disputed the fact that Song of Songs defiles the hands, for the entire world does not compare with the day that Songs of Songs was given to Israel. All the writings are holy, but Song of Songs is holiest of all. If there was a dispute, it was only about Ecclesiastes.’ (Yadaim 3:5)
This text suggests that the inclusion of Ecclesiastes was probably a debatable issue, of doubt because of the radical skepticism of the work. In addition to Song of Songs and Ecclesiastes, the book of Esther was also a debated inclusion (see Zeitlin, 175-78). The evidence that Esther was included late is as follows:
a. The festival of Purim, which is advocated in Esther, is given as a semi-holiday by the Megillat Taanit, which lists the days when fasting is prohibited but which are not noted in the biblical text. This suggests that Esther was not yet accepted as scripture when Megillat Taanit was drawn up (late first century AD?)
b. Later rabbis appealed to Megillat Taanit to support the celebration of Purim rather than the book of Esther.
c. The Talmud notes that ‘Esther does not defile the hands’ (Rabbi Samuel, 3rd century), that the book ‘was composed by divine inspiration to be read but not to be written down’, and that ‘Esther petitioned the sage “Record me for posterity”.’ (Megillah 7a).
d. Several Christian writers of whom the most important witness is Melito, bishop of Sardis (about 170 AD) did not list Esther among the works that the Jewish community considered canonical.
The above considerations suggests at the time of Josephus the status of Ecclesiastes and Esther was unsettled. Esther was probably not accepted as a ‘writing which defiles the hands’ until the second century AD and then due to the pressure of public opinion and the influence of its use in Purim (so Zeitlin, 176). (J.H. Hayes, “The Canon of the Old Testament” in Contemporary Catholic Theology: A Reader, eds. Michael A. Hayes and Liam Gearon [Herefordshire, United Kingdom: Gracewring, 1998], 62-86, here, pp.74-75)
With respect to the debate about the status of the Song of Solomon, one leading expert on this text wrote:
The propriety of inclusion of the Song of Songs in the Canon was apparently questioned from the start and has been vigorously protested in modern times. Yet it must be said that the evidence for its early acceptance, in spite of the objections, is as well attested as that for any other portion of the Jewish-Christian Scripture. It has been regarded and transmitted as canonical by both the Synagogue and the Church.
Whether the allusion to Solomon’s writings in Ecclus 47:15b includes the Son of Songs is doubtful; it is probably of more than a poetic allusion to I Kings 5:12. Similarly, Josephus’ enumeration of the sacred books (Against Apion I 8) does not make clear whether the Song of Songs was counted among the “four books which contain hymns to God and precepts for the conduct of human life.” It is, however, included in the list of sacred books in the Talmud (Baba Bathra 14) and in the Canon of Melito, Bishop of Sardis, who in the latter part of the second century traveled to Palestine to discover what books were considered canonical there. It was translated into Greek by Aquila between ca. A.D. 90 and 130 and later by Symmachus and Theodotion before the end of the second century.
From rabbinic sources we gather that there was some dissension about the canonicity of the Song of Songs at the council of Yabneh (Jamnia) and that Aqiba took an active part in the controversy. This need not mean, as some scholars (notably Graetz) have supposed, that the book had remained outside the Canon until that time. The issue was not whether the book was included in the Canon, but whether it should have been. The dispute arose in connection with another book attributed to Solomon, viz. Qohelet (Ecclesiastes). Rabbi Judah opined (Mishnah, Yadayim III 5) that the Song of Songs defiles the hands (i.e. is tabu or sacred, hence canonical), but Qohelet does not defile the hands, while Rabbi Jose said that the Song of Songs is disputed. Aqiba, however, said, “Perish the thought! No man of Israel ever disputed about the Song of Songs, that it did not defile the hands. The whole world is not worth the day on which the Song of Songs was given to Israel, for all the Scriptures are holy, but the Song of Songs is the Holy of Holies; if they disagreed, it was only about Qohelet that they disagreed.” Rabbi Aqibas’s regarded for the Song of Song as the veritable Holy of Holies moved him also to protest what he regarded as its profanation in the “Banquet House.” “He who trills his voice in chanting the Song of Songs in the banquet house and treats it as a sort of song (zĕmîr) has no part in the world to come” (Tosefta, Sanhedrin XII 10). A similar view is expressed elsewhere, anonymously, “He who pronounces a verse of the Song of Songs and makes a sort of song and pronounces a verse in a banquet house not in its time brings evil to the world” (TB Sanhedrin 101 a). (Marvin Pope, Song of Songs: A New Translation with Introduction and Commentary [AB 7C; Garden City: Doubleday, 1975], 18-19)