Yes. Checkmark the documents/emails you want to delete, or click the checkbox in the column heading to select all. Then click Delete to delete the selected documents/emails.
This can be done from any list, including your In Tray.
Note: If you do not see the delete option, it may be because one or more of the selected emails or documents cannot be deleted. Refer to the FAQ Why can I not Edit or Delete an email or document?