Notes:

• Check to see if there is already a sheet name that is using the desired String
  
  • If there is, clear the cells & reset the UsedRange
    
  • If there isn't, Insert a new Tab, Rename it and move it to the end of the Book
    

InsertTabOrClear (String)

Public Function InsertTabOrClear(myNewName As String)
Debug.Print "InsertTabOrClear"
'----------------------------------------------------------------------------------------------------------
'Defines current tab - returns to it after working with new tab
'Checks for sheet with [String]: If found, CLEAR  data
'                            If NOT found, ADD    sheet
'----------------------------------------------------------------------------------------------------------
Dim iCurrentWS As Long, iTabLoop As Long, sCurrentWs As String, bExists As Boolean, iMatchWs As Long
bExists = False

If ActiveSheet.Name = myNewName Then Worksheets(1).Select
iCurrentWS = ActiveSheet.Index: sCurrentWs = ActiveSheet.Name

For iTabLoop = 1 To ActiveWorkbook.Worksheets.Count
    If Worksheets(iTabLoop).Name = myNewName Then
        bExists = True
        iMatchWs = iTabLoop
        Exit For
    End If
Next iTabLoop

If bExists = True Then
    udfReset99 (iTabLoop)
Else
'-------------------------------------------------------------------------
    'add new sheet: rename
    Sheets.Add after:=Worksheets(ActiveWorkbook.Worksheets.Count)
    ActiveSheet.Name = myNewName
'-------------------------------------------------------------------------
End If
Worksheets(sCurrentWs).Select
End Function

udfReset99 (Sheet.Index)

Function udfReset99(myTempWs As Long)
Debug.Print "udfReset99"
Dim iLastWs As Long
iLastWs = ActiveSheet.Index

'Make sure the current Ws is not the same as the temp
If myTempWs = iLastWs Then
    If iLastWs = 1 Then
        iLastWs = 2
    Else
        iLastWs = iLastWs - 1
    End If
End If

'Select the temp WS and clear the data
Worksheets(myTempWs).Select
Cells.Clear

'Delete the Used Range
Worksheets(myTempWs).UsedRange.Delete
Worksheets(myTempWs).UsedRange

'Go back to the original sheet
Worksheets(iLastWs).Select
End Function