title: Insert and delete from "associations table on EF model"
body: <p>I have to tables "ALUMNOS" and "MATERIAS". In SQL exist another table "ALUMNOS BY MATERIAS". I know this is not necessary in EF model, because exists the properties navigation. But how can insert or delete from this " associations table"??</p>
  
  <p>Thanks in advance!!
  Guille</p>
  
  <p><img src="https://i.stack.imgur.com/oL9mH.png" alt="enter image description here"></p>