You wouldn’t need five tables. Each trit takes up two bits when unpacked into 0,1,2 values.

You can do a full unpacking-via-lookup with a uint16[256] and then do bit shifting and masking to extract the individual trits, but using an extra byte in each entry (or 3 tables) would let you extract with just two shifts.

This starts to vary a lot with the microarchitecture, and there’s the added dimension of SIMD vectorization, so accurate timing in a realistic context becomes important.