If so, then here is a snippet of code which you can use to achieve the operation →
(From row In dt.AsEnumerable()
Let firsthalf = Convert.ToDateTime(String.Format("{0} {1} {2}","01",row("MONTH START").ToString,(CInt(row("YEAR END").ToString)-1).ToString),New System.Globalization.CultureInfo("ro-RO"))
Let secondHalf = Convert.ToDateTime(String.Format("{0} {1} {2}","01",row("MONTH END").ToString,row("YEAR END").ToString),New System.Globalization.CultureInfo("ro-RO"))
Let range = Convert.ToInt32(Math.Abs(DateDiff(DateInterval.Month, secondHalf,firstHalf)))
Let months = CultureInfo.CurrentCulture.TextInfo.ToTitleCase(String.Join(",",Enumerable.Range(0,range+1).Select(Function(s) (firsthalf.AddMonths(s).ToString("MMMM",New System.Globalization.CultureInfo("ro-RO"))))))
Let ra = New Object(){row("MONTH START"),row("YEAR START"),row("MONTH END"),row("YEAR END"),"",months}
Select dt_result.Rows.Add(ra)).CopyToDataTable()
(From row In dt.AsEnumerable()
Let firsthalf = Convert.ToDateTime(String.Format("{0} {1} {2}","01",row("MONTH START").ToString,(CInt(row("YEAR END").ToString)-1).ToString),New System.Globalization.CultureInfo("ro-RO"))
Let secondHalf = Convert.ToDateTime(String.Format("{0} {1} {2}","01",row("MONTH END").ToString,row("YEAR END").ToString),New System.Globalization.CultureInfo("ro-RO"))
Let range = Convert.ToInt32(Math.Abs(DateDiff(DateInterval.Month, secondHalf,firstHalf)))
Let months = CultureInfo.CurrentCulture.TextInfo.ToTitleCase(String.Join(",",Enumerable.Range(0,range+1).Select(Function(s) (firsthalf.AddMonths(s).ToString("MMMM yyyy",New System.Globalization.CultureInfo("ro-RO"))))))
Let ra = New Object(){row("MONTH START"),row("YEAR START"),row("MONTH END"),row("YEAR END"),"",months}
Select dt_result.Rows.Add(ra)).CopyToDataTable()