Public Sub Test()

    Dim SourceRange As Range
    Set SourceRange = ThisWorkbook.Worksheets("SheetA").Range("Q3:X3000")
    
    ' - OR -
'    With ThisWorkbook.Worksheets("SheetA")
'        'Looks in column X for last row:
'        Set SourceRange = .Range(.Cells(3, 17), .Cells(.Rows.Count, 24).End(xlUp))
'
'        ' - OR -
'        'Looks in column Q for last row:
'        Set SourceRange = .Range(.Cells(3, 17), .Cells(.Cells(.Rows.Count, 17).End(xlUp).Row, 24))
'    End With
    
    '*************
    'Cells(3, 17) = row 3, column 17 = Q3
    'Cells(.Rows.Count,24) = row 1048576, column 24 = X1048576
    'End(xlUp) = go up to first non-blank cell.
    '*************

    Dim TargetTable As ListObject
    Set TargetTable = ThisWorkbook.Worksheets("SheetB").ListObjects("Table3")
    
    SourceRange.Copy Destination:=TargetTable.DataBodyRange.Offset(TargetTable.DataBodyRange.Rows.Count).Resize(1, 1)
   
End Sub