At most, you could shove 102 20 bit numbers into the 256 byte eeprom. But.. they would be overlapping, and be pretty difficult to manage at best. Any way to go down to 16 bits instead of 20? That would make it a lot easier to deal with. Then you could fit 128 of them in there, without overlapping. You would know where they started and where they ended without a lot of extra code.
Bookmarks