A few other things that can make a differnce are the following macros

- Remember to backup the workbook first!

Code
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   There is no built-in "compact" option in Excel like the one in Access.
 
 'Have a look at this thread - you will find some code there to get rid of unused rows and columns: 50564
 'This is the version I use (copied from somebody else and adapted a bit):
 
 ' Remove superfluous rows and columns in each worksheet of the active workbook
 
 Sub CleanUp()
 Dim ar As Range, r As Long, c As Integer, tr As Long, tc As Integer
 Dim ws As Worksheet, ur As Range, sh As Shape
 Dim fc As Boolean, fd As Boolean, fs As Boolean
 
 If ActiveWorkbook Is Nothing Then Exit Sub
 On Error Resume Next
 Application.ScreenUpdating = False
 For Each ws In ActiveWorkbook.Worksheets
 Application.StatusBar = "Checking " & ws.Name & ", be patient please..."
 fc = ws.ProtectContents
 fd = ws.ProtectDrawingObjects
 fs = ws.ProtectScenarios
 ws.Unprotect
 r = 0
 c = 0
 Set ur = Union(ws.UsedRange.SpecialCells(xlCellTypeConstants), _
 ws.UsedRange.SpecialCells(xlCellTypeFormulas))
 If Err = 1004 Then
 Err.Clear
 Set ur = ws.UsedRange.SpecialCells(xlCellTypeConstants)
 End If
 If Err = 1004 Then
 Err.Clear
 Set ur = ws.UsedRange.SpecialCells(xlCellTypeFormulas)
 End If
 If Err = 0 Then
 For Each ar In ur.Areas
 tr = ar.Range("A1").Row + ar.Rows.Count - 1
 tc = ar.Range("A1").Column + ar.Columns.Count - 1
 If tc > c Then c = tc
 If tr > r Then r = tr
 Next
 For Each sh In ws.Shapes
 tr = sh.BottomRightCell.Row
 tc = sh.BottomRightCell.Column
 If tc > c Then c = tc
 If tr > r Then r = tr
 Next
 ws.Rows(r + 1 & ":" & ws.Rows.Count).Delete
 ws.Range(ws.Cells(1, c + 1), ws.Cells(1, 256)).EntireColumn.Delete
 Else
 Err.Clear
 End If
 ws.Protect DrawingObjects:=fd, Contents:=fc, Scenarios:=fs
 Next
 Set ar = Nothing
 Set ur = Nothing
 Set ws = Nothing
 Application.StatusBar = False
 Application.ScreenUpdating = True
 MsgBox "Superfluous rows and columns have been removed.", vbInformation
 End Sub
 
 'Over time, you may also accumulate a lot of custom number formats. I use the following code to get rid of them, based on an example by John Walkenbach:
 
 ' Remove unused custom number formats.
 ' Remark: only checks cells in worksheets.
 ' Doesn't check charts, so any formats used in charts but not in cells will be removed.
 ' Uses SendKeys, which can cause problems.
 
 Sub DeleteFormats()
 Dim strOldFormat As String
 Dim strNewFormat As String
 Dim aCell As Range
 Dim sht As Worksheet
 Dim strFormats() As String
 Dim fFormatsUsed() As Boolean
 Dim i As Integer, j As Integer, k As Integer
 If ActiveWorkbook.Worksheets.Count = 0 Then
 MsgBox "The active workbook contains no worksheets.", vbInformation
 Exit Sub
 End If
 On Error GoTo Exit_Sub
 Application.Cursor = xlWait
 ReDim strFormats(1000)
 ReDim fFormatsUsed(1000)
 Set aCell = Range("A1")
 aCell.Select
 strOldFormat = aCell.NumberFormatLocal
 aCell.NumberFormat = "General"
 strFormats(0) = "General"
 strNewFormat = aCell.NumberFormatLocal
 i = 1
 Do
 ' Dialog box requires local format
 SendKeys "{TAB 3}{DOWN}{ENTER}"
 Application.Dialogs(xlDialogFormatNumber).Show strNewFormat
 strFormats(i) = aCell.NumberFormat
 strNewFormat = aCell.NumberFormatLocal
 i = i + 1
 Loop Until strFormats(i - 1) = strFormats(i - 2)
 aCell.NumberFormatLocal = strOldFormat
 ReDim Preserve strFormats(i - 2)
 ReDim Preserve fFormatsUsed(i - 2)
 For Each sht In ActiveWorkbook.Worksheets
 For Each aCell In sht.UsedRange
 For i = 0 To UBound(strFormats)
 If aCell.NumberFormat = strFormats(i) Then
 fFormatsUsed(i) = True
 Exit For
 End If
 Next i
 Next aCell
 Next sht
 ' Prevent error on built-in formats
 On Error Resume Next
 For i = 0 To UBound(strFormats)
 If Not fFormatsUsed(i) Then
 ' DeleteNumberFormat requires international format
 ActiveWorkbook.DeleteNumberFormat strFormats(i)
 End If
 Next i
 Exit_Sub:
 Set aCell = Nothing
 Set sht = Nothing
 Erase strFormats
 Erase fFormatsUsed
 Application.Cursor = xlDefault
 End Sub
 
 'Warning: always save a backup of your worksheet before "cleaning" it!
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