Well if you consider looking up a calculation, than a phone book does a calculation for you.
No, because a phone book doesn't actually look anything up, RAM does.
Well that sounds like a philosophical question, but afaik the aritmetic unit does the look up, not the memory unit.
Yet, unless someone allready knows which person has which phonenumber there is no such book.
By that logic, CPUs don't calculate because they don't know how to do anything until they're instructed to do things.
No, a CPU does a calculation because it changes the input according to a cerrain pattern (given by the instructionset) to from a "new" output. It does not need to "know" that 1 + 1 = 10 it just calculates that every time. The way a CPU is build is fundementally different from a lookup table.
If you want to make a big table for all possible future blocks. Be my guest.
That's the problem. The limited calculation that RAM can do is only useful for real-world crypto problems with amounts of RAM that wouldn't fit in any known universe. (Perhaps unknown ones are larger?)
Its allways the same, either you have time or you have space. You need less time if you have more space, as its with rainbow tables. Still in my book a table is still something that was precalculated and does no calculation whatsoever.