User dbc as the owner of the data dictionary is not allowed to create/drop/alter/insert/update/delete system tables.
You have to create user tables in any other database. It's probably the best to create a new database or user. First you'll have to check for unused diskspace, it depends on your installation (there was an option asking for maximum diskspace during install, i hope you set it to 1GB):
select sum(maxperm) - sum(currentperm)
from dbc.diskspace
where databasename = 'dbc';
The result is the available diskspace. Assign less than that to the new user, e.g.
create user pavan as
password = pavan
perm = 100e+06;
Now, when you log on as user pavan your default database is pavan and you can submit create table. Or just logon as dbc and submit a "DATABASE pavan;" to set it as default database.
For more detals have a look at the manuals, especially the Introduction.
Dieter