Following my previous, unanswered question:
This seems trivial as we're so used to the idea of the two tablets, but still...
"וַיִּתֵּן אֶל־מֹשֶׁה כְּכַלֹּתוֹ לְדַבֵּר אִתּוֹ בְּהַר סִינַי שְׁנֵי לֻחֹת הָעֵדֻת"
"וַיַּגֵּד לָכֶם אֶת־בְּרִיתוֹ אֲשֶׁר צִוָּה אֶתְכֶם לַעֲשׂוֹת עֲשֶׂרֶת הַדְּבָרִים וַיִּכְתְּבֵם עַל־שְׁנֵי לֻחוֹת אֲבָנִים"
The commandments could be written in two columns on one tablet.
Whoever claimed (source needed) that the whole Torah was written on those tablets - what was the division - what part of Torah was on which tablet.
Were they named or numbered? How did they refer to them - "oh, that's written on the X tablet"?
What did they represent as separate parts of the Torah?
So, Why were there two tablets and nobody wondered?