1. The length can be infinitely long, therefore the number of possibilities can be infinitely long.
2. For all practical purposes the space is so large it is infinite. How many possible permutations of 1s and 0s can you get in a 1024 KB program. Many.
3. If we go into the more practical example you raised I doubt there is much difference between the variance in resulting table legs and digital storage applications. If anything, I would say there would be more variation in the software, simply because the high cost of iteration and experimentation (and stricter physical constraints) have narrowed the design space of table legs, in a way which is much less apparent in software.