What is more accurate, thermistor's R-T table or Steinhart-Hart equation?
None can be more or less accurate. They are just two different methods for the same result.

Choose look-up tables, when you need speed, but there is plenty of flash memory.

Choose the equation when you do not have the memory, or you have excess of computational power.

Why none is more accurate than the other? Because both methods need you to insert them data, so they can be as accurate as your data are. If you get better data for the one method then this will be better.

The equation is the most easy way to get accurate results. Less data to input, that are likely provided by the manufacturer.

The table will be slightly more accurate, but just in theory. This is because you create the table using actual measurements and not a theoretical model (that may not be absolutely perfect). Keep in mind that this is very difficult to be done in an accuracy being significant better than the equation, due to measuring errors. And even then the part tolerance will dominate.

If you need more accuracy, just do not use thermistors. (Your tolerance will be even worse than 1%, because of noise, ADC tolerance etc...)