Fix: Extending objects in the API could cause scope errors over multiple tables

- See thread 20075 for the original report

- Basically the issue here was that the object being used for the API
  extension on objects (e.g. `table.ajax` is an object) the object was
  not unique to each API instance, so it was being shared between
  instances and as a result, whatever instance was created last, would
  win!

- Fix is to use a new object each time.