namespace MyProject.Models
{
    using System;
    using System.Collections.Generic;
    
    public partial class MyGlobal
    {
        public int GlobalID { get; set; }
        public int myFileSizeLimit { get; set; }
        public bool myServiceOff { get; set; }
        public string myServiceOffMsg { get; set; }
        public short myViewPageSize { get; set; }
    }
}

After declaration, the next step is to create a mechanism to fetch the global object, so that it becomes accessible from all methods. For this, just create a public method, that create object, fill up values from database etc., and return the global object. Following code snippet represents an example of this process. The GetGlobal method can be called from any method from the Controller.
It is assumed that you have established all database requirements (Entity Framework DB object) in your Controller. It is also assumed that for placing global values in your database, you have only one record in the designated table.

public MyGlobal GetGlobal()
 {
    MyGlobal myGlobal = (MyGlobal)HttpContext.Application["myGlobal"];
    if (myGlobal == null) // if global object is not there already...
    {
        myGlobal = db.MyGlobals.Find(1);
        if (myGlobal != null)
        {
            ControllerContext.HttpContext.Application["myGlobal"] = axcGlobal;  // Put-In the Global Scope...
            return axcGlobal;
        }
        else
            return null;
    }
    else
        return axcGlobal;
  }
    

The last step is to invoke the method GetGlobal() from any method. You may try calling the method like the one decribed in the example code below.

public ActionResult Index()
{
 MyGlobal myGlobal = GetGlobal();
    if(myGlobal != null)
    {
        ViewBag.myServiceOffMsg = axcGlobal.myServiceOffMsg;
    }
    else
    {
        ViewBag.myServiceOffMsg = "default message ...";
    }

    //...
    // Your code follows from here
    // Pass the ViewBag values to your View
    //...

}