I'm currently looking for a fast and efficient way to import an Excel file into a javascript array, and export it also. I also need a way to do the same thing, but the opposite way ...

How to convert an object of objects (initial form of object) into object of arrays of objects (target form of object) I am interested in every way to do this, but I am particularly interested in ...

Use popular 'grammar of data' syntax to filter and subset your two-dimensional JavaScript arrays and more. Here's how to use Arquero for data wrangling in Observable JavaScript and Node.js.