public List<BlobDetails> GetAllBlobsNames()
{
    RichTekstModelDataContext dc = new RichTekstModelDataContext();

    var allBlobs = from b in dc.Blobs
               orderby b.RowVersion descending
               select new {b.Id, b.Size, b.Signature, b.RowVersion};

---> allBlobs.ToList<BlobDetails>();
}

public class BlobDetails
{
    public int Id { get; set; }
    public string Signature { get; set; }
    public int Size { get; set; }
    public System.Data.Linq.Binary RowVersion { get; set; }
}

var qry = from b in dc.Blobs
          orderby b.RowVersion descending
          select new BlobDetails {
              Id = b.Id, Size = b.Size,
              Signature = b.Signature, RowVersion = b.RowVersion};

return qry.ToList();

var qry = from b in dc.Blobs
          orderby b.RowVersion descending
          select new {b.Id, b.Size, b.Signature, b.RowVersion};

var typedQry = from b in qry.AsEnumerable()
               select new BlobDetails {
                  Id = b.Id, Size = b.Size,
                  Signature = b.Signature, RowVersion = b.RowVersion};
return typedQry.ToList();

var allBlobs = from b in dc.Blobs
           orderby b.RowVersion descending
           select new BlobDetails {Id = b.Id, .... };
allBlobs.ToList();