Assuming you meant it all to be in one cell:

Sub abc()
With ActiveCell
.Value = String(14, "x") & Chr(10) & _
String(13, "s") & Chr(10) & String(12, "b")
End With
End Sub

Assuming you want it in separate cells and the 14, 13, 12 string lengths
were intentional:
Sub def()
Dim i As Integer
Dim arr As Variant
arr = Array("x", "s", "b")
For i = 1 To 3
Cells(i, 1) = String(15 - i, arr(i - 1))
Next
End Sub

Assuming the 14, 13, 12 string lengths were unintentional and you want them
to be the same length (here set to 14):

Sub ghi()
Dim i As Integer
Dim arr As Variant
arr = Array("x", "s", "b")
For i = 1 To 3
Cells(i, 1) = String(14, arr(i - 1))
Next
End Sub

Regards,
Greg

"John" wrote:

I want to create within a cell the following text content:
1. xxxxxxxxxxxxxx
2. sssssssssssss
3. bbbbbbbbbbbb

How can I do this?
Regards,