Alisha:
You may want to look at the parts from Cygnal. These parts have internal FLASH that can be programmed as space to put CODE and CODE_SPACE_DATA Tables. The memory CAN be programmed with a software routine that is a part of your application program. The flash programming uses a special mode where an SFR bit is set and then the MOVX instruction accesses the flash instead of the XRAM. Once a data table is written into the flash it is then possible to read it with the MOVC instruction.

Cygnal now has some parts with enough flash that it is bank switched. In these parts the flash can be accessed as data space or codde space