HELP: Filter Top 10 Clients into pivot table when there are more than 600,000 rows/clients

You could use a macro to split the data into 12 sheets - that may get you under the size limit. Create a copy of your data sheet, and delete all columns except Client Name, Region, and Credit Amount (in column A,B, and C), with all else blank. Then run this macro, and create a pivot table from the smaller sheets

If you still have too many unique clients, then you could sort on client name and use subtotals. If you don't have any clients with multiple credit amount entries, then you could just sort based on credit amount descending.

Option Explicit

Sub SplitDataBase()
    Dim C As Range
    Dim DSh As Worksheet
    Dim ASh As Worksheet
    
    Set ASh = ActiveSheet
    With ASh
        .Range("B:B").AdvancedFilter Action:=xlFilterCopy, _
            CopyToRange:=.Range("H1"), Unique:=True
        With .Range("H1").CurrentRegion
            For Each C In .Cells.Offset(1).Resize(.Cells.Count - 1, 1)
                Set DSh = Worksheets.Add(after:=Worksheets(Worksheets.Count))
                DSh.Name = C.Value
                ASh.Range("A:C").AutoFilter Field:=2, Criteria1:=C.Value
                Intersect(ASh.Range("A:C"), ASh.UsedRange).SpecialCells(xlCellTypeVisible).Copy DSh.Range("A1")
                ASh.Range("A:C").AutoFilter
                DSh.Cells.EntireColumn.AutoFit
            Next C
        End With
        .Range("H1").CurrentRegion.Delete
    End With
    
End Sub

You can run my macro after the data is extracted into a table rather than directly into the pivot table. I don't know how to filter the row field if there are too many Clients.