Sub jjj()

    Dim shSrc As Worksheet, shRes As Worksheet
    Dim arr1(), arr2(), arr3(), arrRes()
    Dim lr As Long, r As Long, i As Long, j As Long, k As Long
    
    Application.ScreenUpdating = False
    
    Set shSrc = ActiveSheet
    Set shRes = Worksheets.Add(After:=shSrc)
    
    lr = shSrc.Columns("A").Find(What:="*", LookIn:=xlFormulas, LookAt:= _
        xlPart, SearchOrder:=xlByRows, SearchDirection:=xlPrevious, MatchCase:=False _
        , SearchFormat:=False).Row
    arr1() = shSrc.Range("A1").Resize(lr).Value
    
    lr = shSrc.Columns("B").Find(What:="*", LookIn:=xlFormulas, LookAt:= _
        xlPart, SearchOrder:=xlByRows, SearchDirection:=xlPrevious, MatchCase:=False _
        , SearchFormat:=False).Row
    arr2() = shSrc.Range("B1").Resize(lr).Value
    
    lr = shSrc.Columns("C").Find(What:="*", LookIn:=xlFormulas, LookAt:= _
        xlPart, SearchOrder:=xlByRows, SearchDirection:=xlPrevious, MatchCase:=False _
        , SearchFormat:=False).Row
    arr3() = shSrc.Range("C1").Resize(lr).Value
    
    ReDim arrRes(1 To UBound(arr1) * UBound(arr2) * UBound(arr3), 1 To 1)
    
    For i = 1 To UBound(arr1)
        For j = 1 To UBound(arr2)
            For k = 1 To UBound(arr3)
                r = r + 1
                arrRes(r, 1) = arr1(i, 1) & " " & arr2(j, 1) & " " & arr3(k, 1)
            Next
        Next
    Next
    
    shRes.Range("A1").Resize(UBound(arrRes)).Value = arrRes()
    
    Application.ScreenUpdating = True
    
End Sub

Sub jjj()

    Dim arr1(), arr2(), arrRes()
    Dim lr As Long, lc As Long, r As Long, c As Long, i As Long, j As Long
    
    Application.ScreenUpdating = False
    
    ActiveSheet.Copy After:=ActiveSheet
    
    lc = Rows(1).Find(What:="*", LookIn:=xlFormulas, LookAt:= _
        xlPart, SearchOrder:=xlByColumns, SearchDirection:=xlPrevious, MatchCase:=False _
        , SearchFormat:=False).Column
        
    For c = lc To 2 Step -1
    
        lr = Columns(c - 1).Find(What:="*", LookIn:=xlFormulas, LookAt:= _
            xlPart, SearchOrder:=xlByRows, SearchDirection:=xlPrevious, MatchCase:=False _
            , SearchFormat:=False).Row
        arr1() = Cells(1, c - 1).Resize(lr).Value
        
        lr = Columns(c).Find(What:="*", LookIn:=xlFormulas, LookAt:= _
            xlPart, SearchOrder:=xlByRows, SearchDirection:=xlPrevious, MatchCase:=False _
            , SearchFormat:=False).Row
        arr2() = Cells(1, c).Resize(lr).Value
        
        ReDim arrRes(1 To UBound(arr1) * UBound(arr2), 1 To 1)
        r = 0
        
        For i = 1 To UBound(arr1)
            For j = 1 To UBound(arr2)
                r = r + 1
                arrRes(r, 1) = arr1(i, 1) & " " & arr2(j, 1)
            Next
        Next
        
        Cells(1, c - 1).Resize(UBound(arrRes)).Value = arrRes()
        
        Columns(c).Value = Empty
        
    Next
        
    Application.ScreenUpdating = True
    
End Sub