Save your workbook. If this code doesn't do what you want, the only way to go back is to close without saving and reopen.
Select the data you want to list in one column. Must be contiguous columns. May contain blank cells.
Press Alt+F11 to open the VBE
Press Control+R to view the Project Explorer
Navigate to the project for your workbook and choose Insert - Module
Paste this code in the code pane
Sub MakeOneColumn()
Dim vaCells As Variant
Dim vOutput() As Variant
Dim i As Long, j As Long
Dim lRow As Long
If TypeName(Selection) = "Range" Then
If Selection.Count > 1 Then
If Selection.Count <= Selection.Parent.Rows.Count Then
vaCells = Selection.Value
ReDim vOutput(1 To UBound(vaCells, 1) * UBound(vaCells, 2), 1 To 1)
For j = LBound(vaCells, 2) To UBound(vaCells, 2)
For i = LBound(vaCells, 1) To UBound(vaCells, 1)
If Len(vaCells(i, j)) > 0 Then
lRow = lRow + 1
vOutput(lRow, 1) = vaCells(i, j)
End If
Next i
Next j
Selection.ClearContents
Selection.Cells(1).Resize(lRow).Value = vOutput
End If
End If
End If
End Sub
Press F5 to run the code