Sharing data between stored functions?

I have written a simple web application using pure pl/pgsql and so far it
is working really well (I find it quite easy to maintain as well especially
in terms of form validation).

Basically, apache/php passes receives the incoming web request and calls a
"serve_page" function in postgresql passing the querystring and post values.

The serve_page declares 5 temporary tables to store querystring values,
post values, validation messages, and general data that is going to be
shared between the functions.

Then it parses the page url and calls the appropriate "page render" stored
function.

Throughout the "building" the web page, several of the temporary tables are
written too (about 20-30 rows total would be add to the temporary table).

Once the page "html" is built, the temporary tables are dropped and the
HTML is sent back to php to write to the response stream.

I read in the documentation that temporary tables can cause catalog bloat
or performance issues.....in my context (where only 20-30 rows are written
every request and the table is dropped after rending), could it cause an
issue for many incoming requests?