As to give example
Put them in a another class which will contain the list of object this
class BookList
{
public List<book> book{get;set;}
public List<bookgallery> bookgallery{get;set;}
public List<bookdocument> bookdocument{get;set;}
public List<imagegallery> ImgGallery{get;set;}
}</imagegallery></bookdocument></bookgallery></book>
in you controller
BookList bl=new BookList();
bl.Book=getBook();
bl.bookgallery=new List<bookgallery>.Getall();
bl.bookdocument=BookDocument.GetAll();
bl.ImgGallery=new List<imagegallery>();
</imagegallery></bookgallery>
//Return this class your you will get this in your model
return view(bl);