Model files in CI4

A model can do select in multiple tables, but you will need to write the query yourself, you won't benefit from most of the features the Model class has to offer. You can also not have any entities at all and just use generic objects or arrays. But then again, you won't benefit from the Entity class. Also, with a project that large, the code will quickly become an unmaintainable mess. I doubt that your controller will access all 68 tables every time! Maybe you need to create separate controllers for different part of your application. You can also create some libraries that do the heavy lifting and keep your controller small. Maybe take a look at how I did it in this tutorial. This is just one way to do it. You can choose the way you prefer. But when you have a big application, it's important to have a good structure or else it becomes harder to maintain and develop further.