There are occasions when you'd want more table space and code, the combined total of which would exceed 64KB.
One thing one might do is copy portions of it into SRAM, particularly if it were likely to be updated, and then disable its ROM version.

Another thing some single-boards do is to move a block of memory between code and data space by one mechanism or another. I can certainly imagine a situation within which I'd want to have several table spaces, perhaps one for each device with which I'm communicating. I can't think of one right now that requires a LARGE space, but it could happen.

One thing I've tried with the DS89C4x0's is having parts of the internal FLASH disabled at times so I can use the external memory instead. There are conditions under which one might benefit from swapping external RAM with internal ROM, if the ROM can be disabled under firmware control, so, you see, there are conditions under which one might actually want such a thing. The reason it's not seen more often is because it's not widely supported.

RE