[jayd16]

What would you want that's significantly better than an n-dimensional json array? A sparse table format?

You'll still need to handle the core cell-type parsing. You'll still need to deal with what level of normalization the table used ie are cells primitives or objects or different objects with conflicting structures.

[m_mueller]

an n-dimensional json array still doesn't come with strong type information (other than str/null/decimal/int) for the fields and it doesn't give you a guaranteed shape either. also, there is no standard how to declare the field header labels. also, it's not binary, thus very inefficient for numerical data. there are various data formats that help in those regards, but none of it is standardized, hence all our fingers being sticky from the glue.