How to know spid which is filling tempdb from temp table name in sybase
The best is to use the montables. Make sure you have mon tables activated. Once verified you can issue the following select statement:

select SPID, DBName, ObjectName, PartitionSize
from master..monProcessObject
where DBID = tempdb_id(SPID)
order by SPID


for more information please see the official Sybase docs: http://infocenter.sybase.com/help/index.jsp?topic=/com.sybase.infocenter.dc00967.1550/html/MigrationGuide/MigrationGuide14.htm