Sparse data on subsequent pages is not handled properly in Tables API

Tables collections with sparse data will sometimes error when paging through results. The code that is responsible for adding new headers is not working correctly and the table is rebuilt with no data in the UI.

Start by reproducing the failure while paging through sparse data in the Tables API and inspect the code responsible for adding new headers. Trace how the table is rebuilt in the UI; done means subsequent pages no longer error and the table retains its data.

Written by the indexing model from the issue text.