This is used to build compact tables that can be used to create things like entity mappings It also provides simple load/save functions to save and then load string tables along with other simple types (UInt8..UInt64, Int8..Int64, Float32, Float64, vectors of those types, and String) to/from a file.
Doing so can eliminate a lot of JITing time needed just to parse and then create a table from Julia source, and when Julia can be used to build executables, allows the tables to be updated without recompiling the executable.