The following code will create a letter + 6 figure password in column B for each name in column A, until there is a gap. These are not necessarily unique, but chance is pretty good.
MD

Sub NewPass()
Do
    If ActiveCell.Offset(0, -1) <> "" Then
        ActiveCell.Formula = Chr(Int((26 * Rnd) + 97)) & Format(Int(1000000 * Rnd), "000000")
        ActiveCell.Offset(1, 0).Select
    Else
        Exit Sub
    End If
Loop
End Sub