It literally does not describe a file, and does not literally describe the data layout of anything on disk (though with enough knowledge, you may be able to infer facts about probable layouts).
Huh? Depends on the DMBS, but each InnoDB table is a file.
And the schema determines the file structure.
A table isn't a schema, it is a component of a schema, and most databases don't use InnoDB.
So if you have the schema, you have the tables.
"Determines" is too weak: it must be "is". If "schema is file layout" is true, then sure, a schema is a file layout. But if it is merely "schema determines file layout", then no, a schema is not a file layout.
I think it's a moot point anyway because the language is broader than just files in the filesystem sense, which is basically what the court said too.