I have two tables in my database, one for "sales" informations and the other for "sale content" (items). What is the best method to present this using the laravel models? For example, is it better to create a model for each table or can we only use one?
A Model for each table - you cannot use one Model for multiple tables.
Laravel tries to infer the table name from the Model name based on lowercase pluralisation - so if your Model is called Sale it will presume that the table is called "sales". If your table is something else, you defined the table in the Model using :
protected $table = "online_sales";
Then you will need to define the relationships between the two models - the documentation is here : https://laravel.com/docs/8.x/eloquent-relationships