Consider chainging the type of key in the Column interface to improve type safety.

[CriusNyx]

In your Column interface on line 47 of index.d.ts consider changing the type of key of the following.

key : keyof TRow

This will cause the compiler to throw a type error when developers use a key that is not supported by their TRow interface.

[nstepien]

Rows are left generic so the rows can be a nested structure, or an Immutable.js object for example.