speed up creation of a table

Hello,

I have two questions concerning space and time required to
load huge volume of data in the DBMS.
To note I use JDBC interface to load the schema and data in the postgresql

In order to create the tables contained in my database
I use the command stmt.executeUpdate("CREATE TABLE t1 .... inherits
(t2));
is there any way to speed up the creation of a table in postgresql????

My application creates a lot of tables in which at the beginning are
stored
few records. I woule like to reduce the size DBMS allocates (8K) every
time needs more space? Can this be achieved without reducing BLCKSZ
parameter since I suspect that reducing BLCKSZ will reduce querying
performance. Is that so??

Is it possible to reduce DBMS size e.g. to 4K during loading and
set it back to 8K when querying?

Thank you in advance
Sofia Alexaki