here is the updated code
Sub blah()
Dim WSInput As Worksheet
Dim WSOutput As Worksheet
Dim LastRow As Long
Set WSInput = ThisWorkbook.Worksheets("Sheet1")
Set WSOutput = ThisWorkbook.Worksheets("Sheet2")
LastRow = FindLastRow(WSInput, "A")
With WSOutput
For i = 1 To LastRow
temp = temp & WSInput.Cells(i, 1) & " - " & WSInput.Cells(i, 2) & vbCrLf
Next i
.Cells(1, 1) = Left(temp, Len(temp) - 1)
End With
Set WSInput = Nothing
Set WSOutput = Nothing
End Sub
Function FindLastRow(ByVal WS As Worksheet, ColumnLetter As String) As Long
FindLastRow = WS.Range(ColumnLetter & Rows.Count).End(xlUp).Row
End Function