Highlight, press SHIFT & DELETE answer YES and they will disappear into the ether. If there are a lot of them - hold down CONTROL and you can highlight as many-or as few as you want, then as above.
That is a package that includes very, very secure public key encryption software, so that you can send email or anything else without anyone knowing what it is.
Also has a file and free space eraser, that works very securely.