Предполагая, что данные находятся в столбцах A, B и C:
Sub G()
Dim r&, x&, cnt%, arr
Dim wksOutput As Worksheet
Dim this As Worksheet
x = 2 '//Skip header
Set this = ActiveSheet
Set wksOutput = Sheets.Add(After:=Sheets(Sheets.Count))
With wksOutput
For r = 2 To this.Cells(Rows.Count, 1).End(xlUp).Row
arr = Split(this.Cells(r, "C"), Chr(10))
cnt = UBound(arr) + 1
.Cells(x, "A").Resize(cnt) = this.Cells(r, "A")
.Cells(x, "B").Resize(cnt) = this.Cells(r, "B")
.Cells(x, "C").Resize(cnt) = Application.Transpose(arr)
x = x + cnt
Next
End With
End Sub