I think I understand the question to mean that the user project is configured (or can be configured) to get data input from the processor through write operations to a memory-mapped register, and the question is whether a large dataset can be coded into a C program and read from flash by the processor and written to the processor. In that case, the answer is yes, but depends on just how much data needs to be stored. The SPI flash on the board is pretty big (32MB). The address space devoted to the SPI is, I think, 256MB. The immediate limit using the standard program/flash/run method will be 16MB, since the SPI flash controller issues 3-byte address commands to the flash, and that's the limit of 3-byte addresses. There are more complicated methods to transfer a program directly into memory, decoupling it from the flash, and then having it send its own commands to the flash which would just issue a single stream read with automatic increment, which would have effectively unlimited memory capacity.