Is it possible to use a collection document as a table in MongoDB?

Question

MongoDB

There is a DB, in it a collection, in it the document, in it a key on value-array.
This array also is supposed to be used as the table.
Why not documents right away: because you don’t really want to have a 12-byte index for each record, there are a lot of records (tens to hundreds of thousands) planned.
I heard about document size limits , but it seems that it can be adjusted.
Array elements: objects
Well, how does Monga relate to the names of keys in objects, they will be repeated (for example: name, price, img
Why Monga: because Node, and even benches please with superiority over SQL-DBMS
Is this normal? For the purposes of: writes, reads (well, just by array index), performance?
I recently started learning Mongu and even everything is too complicated compared to MySQL))