You can edit an interaction by locating it on the Interactions grid and either double-clicking it, or by selecting the row, then clicking on the View/Edit button and then Interactions. The Date/Time is also a hyperlink that you can click on to edit the interaction.
An interaction can be deleted from the interactions grid by selecting the specific interaction and clicking on the trashcan which is located on the far right end of the grid. You will get a confirmation message asking you to confirm that you really want to delete the interaction. You can cancel or continue and the interaction will be deleted.