DynamicModule[{data = "some\ndata"}, EventHandler[
  Framed[Pane[
    InputField[Dynamic[data], String, ContinuousAction -> True, 
     Appearance -> None, FieldSize -> {30, {1, Infinity}}], 
    ImageSize -> {400, 100}, ImageMargins -> 0, 
    AppearanceElements -> {}, FrameMargins -> {{0, 0}, {0, 0}}, 
    Scrollbars -> {True, True}], Background -> White, 
   FrameMargins -> 0, FrameStyle -> Gray]
  , {
   "ReturnKeyDown" :> 
    FrontEndExecute[{NotebookWrite[InputNotebook[], "\n", After]}]
   }]]