Yes, you can. You didn't provide very much information, but what I think you are talking about can be done by performing these steps:
Across the top, where it says "File, Edit, View, etc" Click on Lists, then Item List, at the bottom of that screen, there is a button that says "Item", when you click on it, there will be a dropdown, that will allow you to add a new item, edit and item, delete and item etc..." If you are adding new items click new, if you are editing, click edit.
At the very top of the scree that pops up there is a field to enter item type, this can be customized to the type of item you want to choose.
I hope this answers your question, if not please provide additional details about your problem and I will be happy to help.