I have the following questions :
1. If I want to close the index table that is currently being used to load data, how do I find the current index table name?
2. If I close the current index table that is used for loading data, would CMOD create a new table and tablespace for adding new rows.
3. How can I reopen a closed index table if it has scope to add additional data?
1) You don't need it. Use arstblsp.
2) Yes.
3) You don't. You close the current table and open a new one.
It sounds like you might want to explore table partitioning -- a feature that wasn't available back when CMOD was written, but is a built-in feature of DB2 now.