Sort Through Schema Tables To Find If Particular Vendor Number Exist

I would like to be able to sort through a schema's tables to find if particular vendor numbers exist. The decode cross tab works fine, except that it needs static data for each table. How can I code a PL/SQL to populate the table_name and give a count for each row? See example below:

col table_name format a15
set numwidth 10
set lines 1000
set pages 50

select b1.table_name,
count(case when a.vendor='86444' then 1 else null end) "86444",
count(case when a.vendor='86445' then 1 else null end) "86445",
count(case when a.vendor='86469' then 1 else null end) "86469",
count(case when a.vendor='86470' then 1 else null end) "86470",
[code]........