try:
Sub CommandButton1_Click()()
BlockSize = 10 '<<<you can adjust this.
DestRow = 0 'one less that the destination row.
Set SourceSheet = ActiveSheet
Set DestnWB = Workbooks.Open(Filename:="C:\Users\kenneth\Desktop\TEST\OUTPUT.xlsx")
Set DestnSheet = ActiveSheet
With SourceSheet
lr = .Cells(.Rows.Count, "A").End(xlUp).Row
For rw = 1 To lr Step BlockSize
DestRow = DestRow + 1
SourceSheet.Cells(rw, 1).Resize(Application.Min(lr - rw + 1, BlockSize)).Copy
DestnSheet.Cells(DestRow, 1).PasteSpecial Paste:=xlPasteAll, Operation:=xlNone, Skipblanks:=False, Transpose:=True
Next rw
End With
DestnWB.Close True
Application.CutCopyMode = False
End Sub