I tried to cast it directly like this

And get error: Cannot implicitly convert type 'System.Linq.IQueryable' to 'System.Collections.Generic.List<TEntity>'

Then I found that it has method to convert to list or cast to object  and it can be either casted to TEntity by calling cast<object> or converted to List<TEntety>

By calling .ToList(List<TEntety>)

For example here us property :

        public List<TEntety> test

        {

            get

            {

                 Return (from tentety in db.TEntety

                            select tentety).ToList<TEntety>();

            }

        }