The earthly tablets of the 10 Commandments given by Jesus to Moses were stored in the Ark of the Covenant in the earthly sanctuary which was patterned after the pattern that Jesus showed Moses. Note, Hebrews 8:1-6
"1Now the point in what we are saying is this: we have such a high priest, one who is seated at the right hand of the throne of the Majesty in heaven,
2a minister in the holy places, in the true tent
a that the Lord set up, not man.
3For every high priest is appointed to offer gifts and sacrifices; thus it is necessary for this priest also to have something to offer.
4Now if he were on earth, he would not be a priest at all, since there are priests who offer gifts according to the law.
5They serve a copy and shadow of the heavenly things. For when Moses was about to erect the tent, he was instructed by God, saying,
See that you make everything according to the pattern that was shown you on the mountain.
6But as it is, Christ
b has obtained a ministry that is as much more excellent than the old as the covenant he mediates is better, since it is enacted on better promises."
The bold text that I highlighted above are key texts that prove that the original tablets are in the heavenly sanctuary where Jesus is mediating as our Great High Priest as we speak.
In Revelation 11:19, the Apostle John was clearly shown the
Ark of the Covenant in the heavenly sanctuary. Note the text below:
"Then Gods temple in heaven was opened, and
the ark of his covenant was seen within his temple. There were flashes of lightning, rumblings, peals of thunder, an earthquake, and heavy hail."