I use the higher speeds when I'm sewing long seams like borders. If I need to pin, I use a dot of glue and go full steam ahead.
You will find that if you move your machine to the end of the table, so it sits directly on top of a table leg, it will lessen the vibration. If you're using something lightweight, like a card table, you'll get vibration no matter what. But if your table is solid and has good support underneath, such as a beam connecting the legs under the table's surface, it won't vibrate at all.