Hi Kathy,
I think each option is fine but I would probably go for your three table option because:
1. Telephone, fax and pager may represent different entities - later you may want to add another field to telephone, but not to fax and pager.
2. Easier SQL. If you want the list of telephone numbers only, you don't need to add a where clause filtering on telephone number. You would if everything is in the one table.
3. You can have the best of both worlds by unioning the three tables to create a contacts view to represent the one table option. e.g,
create view contacts as
select id, number, 'telephone' as type from telephones
union
select id, number, 'fax' as type from faxes
union
select id, number, 'pager' as type from pager
Richard