What was the significance of the ornaments that Eliezer gave Rivkah?
Rashi and Targum Yonasan: The nose-ring that weighed a Beka (half a Shekel) hinted at the half-Shekel 1 that every Yisrael gives every year for Korbanos Tzibur; the two bracelets (Tzemidim) that weighed ten gold Shekalim, hinted at the two Luchos (Metzumados - exactly similar), and Aseres ha'Dibros that were engraved on them.
See Rashbam.
Why did Eliezer give the ornaments to Rivkah before he knew that she was from the right family?
Rashi (to 24:23): Because, on the merit of Avraham, he felt certain that Ha'Kadosh Baruch Hu had granted him success. 1
Rashbam, Da'as Zekenim and Ramban: He actually asked her first about her family, only the Torah inverts the order, because it wants to first finish telling us what Eliezer did and her response (Rashbam). 2
Malbim: He was not required to find a girl from Avraham's family. Ha'amek Davar - Ta'anis 4a implies that giving to him and the camels to drink sufficed. 3
Gur Aryeh (to 24:23): Eliezer wanted to invoke the symbolism in the jewelry's weight (refer to 24:22:1.4). He saw that it was a fitting and auspicious time, so he gave it to her immediately, without any interruptive speech that would ruin his Kavanos.
Also refer to 24:23:151:1.
This is borne out by what Eliezer told Rivkah's parents (See 24:47). The Ramban, on the other hand, proves his point from the fact that the Torah omits the verb "and he placed," implying that he only took the ornaments out, but did not give them to her until after he had asked her about her family.
Perhaps this is because the Gemara said only that he prayed improperly, lest she have a blemish. It did not say, lest she not be from Avraham's family! (PF)
Why does it say that the bracelets were on her hands? It does not even say that he gave them to her!
Ohr ha'Chayim: They fit her hands perfectly - another sign that HaSh-m intended her for Yitzchak.
QUESTIONS ON RASHI
Rashi writes: "'[Weighing] a half-Shekel (Beka)' - He hinted to the Shekalim that Bnei Yisrael [would later bring]." How do we know that there was any symbolic meaning in the jewelry's weight?
Gur Aryeh: We would expect the Pasuk to describe a large gift, but a half-Shekel is a small amount. Rather, the weight had symbolic meaning.
Rashi writes: "He hinted to the Shekalim that Bnei Yisrael [would later bring to the Mikdash]." Why did he allude to this specifically?
Gur Aryeh: The Shekalim would be used to fund the Avodah. Refer to 24:22:1.4:1.
Rashi writes: "He hinted to the Shekalim that Bnei Yisrael [would later bring]." Why did he do this, if Rivkah would not understand the symbolism?
Gur Aryeh: Although she did not understand, her Mazal understood. 1
Gur Aryeh: See Megilah 3a. In other words, the symbolism would nonetheless be reflected in Rivkah and her offspring. (CS)
Rashi writes: "He hinted to the Shekalim... to the two Luchos... to the Aseres ha'Dibros." Why specifically these?
Gur Aryeh #1: 'The world stands upon three things; upon Torah, Avodah and Gemilus Chasadim' (Avos 1:2). Eliezer saw that Rivkah had attained the trait of Gemilus Chasadim. He hinted that her offspring would also merit Torah (represented by the bracelets), and Avodah (represented by the Nezem); now she would have all three.
Gur Aryeh #2: These three things are unique traits of Bnei Yisrael, the pillars upon which the world stands. They were granted to the Avos - Chesed to Avraham, Avodah to Yitzchak, and Torah to Yaakov; they in turn passed them on to their descendants. Eliezer hinted to her that since she was a Gomeles Chasadim, she would bear the nation that would excel at all three.
Gur Aryeh #3: Korbanos show the purity and perfection of Nefesh 1 in Bnei Yisrael; and Torah is perfection of Sechel. Eliezer hinted to these two, to tell her how fortunate she was to attach herself to such a holy nation.
See Gur Aryeh to Shemos 25:2.
Rashi writes: "He hinted to the Shekalim... 'Two bracelets' - he hinted to the two Luchos." Why did he hint to the Korbanos with a nose-ring, and to the Luchos with bracelets?
Maharal (Derech Chayim 1:2, p. 29): The Korbanos are described as a "pleasing aroma" (Rei'ach Nicho'ach) before HaSh-m. The Luchos were handed (so to speak) by HaSh-m to Moshe's hands (Devarim 9:15).