For Question 1, the naming convention for a pivot table between two multiple word tables would be to concatenate the singular form of the two table names in alphabetical order, separated by an underscore. So in this case, it would be:
php artisan make:migration create_schema_property_schema_type_table
For Question 2, it is generally best practice to keep each table in its own migration file, rather than consolidating them into a single file. This makes it easier to manage and track changes to each table separately. However, you can still consolidate foreign key migrations into a separate file if you prefer.