Sounds like you have some delete options set up in your database so that deleting a record in table A deletes related records in Table B. If you get enough of these options specified in different table occurrences, you can get a cascade of deleting records that clears most of the records out of your database.
WHere do I change these options are they in each relationship or in the menu??
Start with the layout from which you deleted a record and this "cascade" then took place.
Open Layout Setup and note the name in "show records from".
Now open Manage | database | Relationships and find the table occurrence box with this same name.
Double click each relationship line that links it to other occurrences.
There's a pair of check boxes marked "delete....". In these dialogs. If you clear any of these that specify a delete in the related occurrences, you can then delete a record on your layout and no cascade will take place.
This is just a "brute force" fix of the problem. You'll need to analyze the delete settings in all your relationships to figure out which ones you need to keep referential integrity and which should not have been specified.