What do you call this kind of dictionary inside an array thing?
name: 'Category 1',
name: 'Subcategory 1'
name: 'Subcategory 2'
name: 'Category 2',
name: 'Subcategory A'
name: 'Subcategory B'
Edit: it seems like you are asking if there is a special name for "array of objects." No, there isn't, this is just a ubiquitous idea in programming in any language. I don't even know anyone who would call it a pattern even.
The point of an array is that it can hold more than one thing of each kind. The inner array is an array of objects. It's called
children. Children is plural. This is correct.
The outer array holds just one object. Perhaps the programmer intends to add more objects later. Perhaps it's being passed to a method that expects an array. I don't know, and it's not possible to infer anything besides "an array of one object."