The laws of physics are much simpler than the detailed structure of a given table

It is not practical to simulate everything down to the level of the laws of physics. In practice, you usually have to come up with much coarser models that can actually be computed within a reasonable time and most of the experimentation is needed to construct those models in the first place so that they align sufficiently with reality, and even then only in certain circumstances.

You could maybe use quantum mechanics to calculate the planetary orbits out for thousands of years, but it’s much simpler to use Newtonian mechanics for that, and that’s because the planetary motions happen to be easily modelable in that way, which however isn’t true for building rocket engines, or predicting the stock market or global politics.

It is not practical to simulate everything down to the level of the laws of physics. In practice, you usually have to come up with much coarser models that can actually be computed within a reasonable time and most of the experimentation is needed to construct those models in the first place so that they align sufficiently with reality, and even then only in certain circumstances.

You could maybe use quantum mechanics to calculate the planetary orbits out for thousands of years, but it’s much simpler to use Newtonian mechanics for that, and that’s because the planetary motions happen to be easily modelable in that way, which however isn’t true for building rocket engines, or predicting the stock market or global politics.