http://www.torah.org/advanced/mikra/5757/sh/dt.57.2.05.html
... the original plan was for the people to hear more than just these ‘Aseret haDibrot; whether they should have heard the entire Torah or just the rest of Sefer haB’rit (through 23:19) is unclear. What is implicit in these verses is that it was the people’s fear that interrupted the revelation and “changed the rules” such that Mosheh would receive the rest of the revelation alone and transmit it to the people.
This would also explain an interesting switch in terminology in the Torah relating to the Tablets. Whereas they are called Luchot haB’rit - “the Tablets of the Covenant” in one section of Sefer D’varim (9:9-15), they have a different name in reference to their placement in the Mishkan:
You shall put into the ark the Edut (testimony) that I shall give you. (25:16).
These tablets are called Edut because they testify to the Revelation. In other words, these ‘Aseret haDibrot were not committed to graphic representation on the tablets because of their inherent importance, but rather as a testimony to the Revelation which every member of the B’nei Yisra’el had experienced...
Ping to #38 and up thread.
God did not say the Ten Commandments in public because only those ten were of lasting importance. The narrative clearly indicates God was going to continue speaking more commandments in public, but relented because the Children of Israel felt they could not bear it.