First of all, there was no specific tablet which was written by God’s finger. I encourage you all to read and understand the following verses:
Exodus 31:18 says, “And he gave to Moses, when he had finished speaking with him on Mount Sinai, the two tablets of the testimony, tablets of stone, written with the finger of God.”
Deuteronomy 9:10 says, “And the LORD gave me the two tablets of stone written with the finger of God, and on them were all the words that the LORD had spoken with you on the mountain out of the midst of the fire on the day of the assembly.”
Luke 11:20 says, “But if it is by the finger of God that I cast out demons, then the kingdom of God has come upon you.”
Looking at these verses, we sometimes may believe that God has a finger and it is Powerful and writes. Saying this actually is not fully incorrect since God has made us in His own image and he is full of Might and all Powerful. But, as per these verses we see another picture. I was going through one of the commentary by Geneva Study Bible for Luke, it makes it very clear, “That is, by the power of God: so it says in Geneva Exodus 8:19.” So does the Wesley’s notes says, “If I cast out devils by the finger of God – That is, by a power manifestly Divine. Perhaps the expression intimates farther, that it was done without any labour: then the kingdom of God is come upon you – Unawares, unexpected: so the Greek word implies.”
Getting back to the main question, understanding the Bible in context, a message was revealed to Moses and he wrote it down. I was listening to one of the recording by Allama Ibrahim Yusuf (Christian scholar) on the same topic, and he humorously says, “There are obviously no Printing Machines available with God that he writes stuff using various Dyes as well as plates.” According to Exodus 32:19, it says like this, “And as soon as he came near the camp and saw the calf and the dancing, Moses’ anger burned hot, and he threw the tablets out of his hands and broke them at the foot of the mountain.” This verse clearly says that Moses breaks the tablets. Not only he breaks, while breaking the tablets, Moses was extremely angry. God had already revealed his commandments to mankind; still people broke the law and were worshiping the calf. So saying that tablets are by God to them does not show any importance during that event since people had already broken the law. Obviously when rules are already broken, what importance does that piece of stone hold? Now, if we read Exodus 34:1, it says like this, “The LORD said to Moses, “Cut for yourself two tablets of stone like the first, and I will write on the tablets the words that were on the first tablets, which you broke.” Moses makes a new set of tablets which went for long but within time they were lost. If we see the history through the old testament, nations had been so much corrupted that even if those second sets of tablets would have been available, people may have started worshiping them itself in the name of God. Lord knew what was required and what not. The commandments were memorized, shared, copied as we still have it; there is no point of having the original tablets or raising a question that “Is the Ark of the Covenant, which God gave to Moses, still in the hands of the Jewish people or is it lost in history?”