Do you have any specific requirements to match records to lookup tables or it just a straight load - that is an insert?
Do you have any specific performance requirements?
The easiest and fastest way to load data into Oracle is via external file and parallel query/parallel insert. Remember that parallel DML is not enabled by default and you have to do so via alter session command. You can leverage multiple CPU cores and direct path operation to perform the load.
Assuming your database is on a linux/unix server - you could NFS load the file if it is on a remote system, but then you will be most likely limited by network transfer speed.
suggest you configure dbfs and load from dbfs to get the fastest loading speed.
what kind of environment and table you gonna maintain, if 500GB data load per day then it wud be 20 TB size table in one month since existing table size is 5 TB.
Could I know your exadata environment in detail.