Here is a function I found that can trim down a datatable/dataview to a limited number of rows.  Basically, it’s like doing a “TOP X”.

''' <summary>
''' Will return a dataview with only the top "number" of rows.
''' </summary>
''' <param name="myDataView">dataview to "trim"</param>
''' <param name="number">the number of rows to return</param>
''' <returns></returns>
''' <remarks></remarks>
Public Shared Function GetTopDataViewRows(ByVal myDataView As DataView, ByVal number As Integer) As DataView
    Dim tableToClone As DataTable = myDataView.Table.Clone
    Dim i As Integer
    For i = 0 To number - 1
        If i >= myDataView.Count Then Exit For
        tableToClone.ImportRow(myDataView(i).Row)
    Next
    Return New DataView(tableToClone, myDataView.RowFilter, myDataView.Sort, myDataView.RowStateFilter)
End Function

I didn’t write this, credit goes to this post.