Entity Framework Inheritance Code First

I am new to EF and as per this tutorial I have set up my code-first classes to have base calls TableA's ID as primary and foreign key for TableB as below:

[Table("TableA")]
public abstract class TableA
{
    [Key]
    [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
    public int ID { get; set; }
    public string Description { get; set; }
}

[Table("TableB")]
public class TableB: TableA
{
    [Key]
    public int ID { get; set; }        
    public int Width { get; set; }
}

In controller when doing a query:

 var a = db.TableB.ToList();

I get 0 for tableB IDs. But while debugging I can see the base class having the appropriate IDs. so I did a loop and inside it assigned IDs using item.ID = ((TableA)(item)).ID;.

The above works as in it assigns the IDs so I can see them in my view, but is this the right way to do it? Is there any other solutions?

EDIT : Here is the dbcontext:

public class Context : DbContext
    {
        public ProductContext()
            : base("DefaultConnection")
        {
        }

        public DbSet<TableA> TableA { get; set; }

        public DbSet<TableB> TableB { get; set; }
    }