Using e.g. a single zettabit-sized look-up table to give the 64-bit result of a multiplication of two 32-bit numbers suffers from a similar problem. But if we're talking about practical concerns there are already faster methods than random access in >100 exabytes of memory. And if we're talking theoretical concerns your answer still hasn't addressed the question of how to multiply numbers fast.
Factorize big numbers, sort an array, beat stockfish at chess, create a SOTA microkernel OS from English description. All O(1) with lookup table!
It's not how complexity works.