There are quicker ways if this takes too long:
If the table you're talking about is a true Excel Table then this snippet might do it for you (you only need the selected cell(s) to within such a table - the whole table excluding the headers will be processed):
Sub blah()
For Each cll In Selection.ListObject.DataBodyRange.Cells
With cll
.HorizontalAlignment = xlLeft
.VerticalAlignment = xlCenter
.WrapText = False
.MergeCells = False
If TypeName(cll.Value) = "String" Then .NumberFormat = "@"
End With
Next cll
End Sub
but if it's not a true table then this snippet will act in a similar way on only the selected cells:
Sub blah2()
For Each cll In Selection.Cells
With cll
.HorizontalAlignment = xlLeft
.VerticalAlignment = xlCenter
.WrapText = False
.MergeCells = False
If TypeName(cll.Value) = "String" Then .NumberFormat = "@"
End With
Next cll
End Sub