eShopOnWeb | Sample ASP.NET Core | Architecture library

I have two partials. One is _ProductList.cshtml:

What is the purpose of using the => operator with public fields in a C# class? I saw this being done in the unit test code in the eShopOnWeb ASP.NET Core project hosted on GitHub. Is it actually a property with the => operator referring to the value returned from the getter method? The code in question is shown below:

I am building a new ASP.NET Core 5 MVC app. I want to use clean architecture as outlined in Microsoft's web app architecture ebook.

I am also studying eShopOnWeb sample application available here :

https://github.com/dotnet-architecture/eShopOnWeb

What I understand from the ebook and sample app is - EF Core entity classes (say Customer, Product, Order) will go inside ApplicationCore project's Entities folder. The DbContext will be in Infrastructure project.

My confusion is: is it alright to add data annotation schema attributes such as [Table], [DatabaseGenerated], and [Key] on these entity classes inside ApplicationCore project? If not, where should I add these data annotations?

Any advice in this regards is highly appreciated.

Thank you.

1. Using ASP.NET Core MVC 3.1.
2. Added security using the identity scaffolding.
3. Created default groups following the instructions from eShopOnWeb (https://github.com/dotnet-architecture/eShopOnWeb/blob/master/src/Infrastructure/Identity/AppIdentityDbContextSeed.cs)
4. Able to seed the database and create
   3 groups: Admins, Managers, Users
   3 users: Admin, Manager, User
   assign the user to respective group.
5. I need instructions on how to accomplish assigning the roles to users from the User Management form (MVC pattern) at the time when I create a user or need to edit the roles for the users. Also I need MVC pattern not Razor pages like here https://github.com/bhrugen/Uplift/blob/master/Uplift/Areas/Identity/Pages/Account/Register.cshtml.cs
   I presume I need to create the ViewModel which would include entries from dbo.AspNetUsers, dbo.AspNetRoles, dbo.AspNetUserRoles for that but not sure what exactly I need and how to perform.
6. Here is the desired functionality of the form