Is there a name for Craft 3's database model?
Craft uses a fairly typical relational model, where most1 custom fields have a single column in the content table, set to an appropriate column type chosen by the field type. Unlike EAV, which crams all data into a fixed schema, Craft’s schema will change over time based on the custom fields you’ve configured.
There are both performance and storage benefits to this. However there’s one significant downside, which is that it’s possible to hit row size limits if you have hundreds of custom fields (particularly with MySQL). We’re going to address that in Craft 4 by splitting the content table up into multiple tables – one per field layout.
1There are a couple exceptions: relational fields (like Entries) which store their data in the relations table, and fields that store nested elements such as Matrix and a couple third party field types, which create their own field-specific content-esque tables.