Hello John,
If i didn't miss something, ther's no the concept of multiple "routing table". You can think at Jasmin routing as a single routing table for each outgoing and incoming flows so a total of 2 routing tables for incoming and outgoing messages.
When a message need to be sent, all routes get evaluated in their order, the first matching one is used without go trought the other routes.
If you have 2 (or more) upstream connections, you have to create an smppccm foreach of them.
After that you should define a default route (only one defaulte route is accepted) and it doesn't need any filter.
After that you have to define some conditions to recognize messages, these rules are named "filters", they are basically conditions applied to different variables.
The last step is to define some routong rule that link one (or more) filter to a connector.
There are also Random Roundrobin rules and failover rules that are well described in the documentation.
Hope it may help you.