Wilkie, do you mean the friend suggestions which appear under the heading 'Requests' at the top of your screen, which has things like....
2 Friend Requests, 6 Event Invitations, 27 Friend Suggestions, 10 Other Requests
(This is a fixed list which only goes away if you go in and either accept or ignore each one.)
If so, these 'friend suggestions' have actually been made by people and haven't been automatically generated by facebook. So, when someone adds a new friend or accepts a friend request, there is an option for them to suggest other friends that person might know.... so you have been suggested as someone these other people (might) know. You can also go into any of your existing fields and suggest them to other people.
Below the list of 'Requests' on your main screen, there is another heading for 'Suggestions' - This one is automatically generated by FB and will show friends of friends and sometimes pages that friends are a fan of...... So you'll see loads of people in here that you probably have no real connection to, other than one of your friends happens to know them.