So my potentially dumb question is really three potentially dumb questions, but they all have to do with the FeatureTable, so hopefully asking all three of them in the same place will be OK.
I have things set up properly, I believe, as I can click the Feature and the data will show up in the FeatureTable, but the Feature doesn't highlight, and it doesn't register as actually selecting it. (It shows, Features: 1, Selected: 0). The way I'm doing it is as follows:
#1 To highlight on the map, yes it does need to be visible. Either that or add graphics to the map or to a graphics layer.
#2 featureTable.selectRows() will take either a number or a graphic, but you have "0" as a string try just featureTable.selectRows(0)
#3 There are two options that I have used:
a. You can set the definitionExpression for the feature layer for the table to something that is impossible, like OBJECTID IS NULL. That should give you an empty table.
b. Create an empty FeatureLayer in your app to use as the layer for the table, query the layer with 109k features and the use applyEdits to send them to the empty layer. You would need to delete them as well using applyEdits when you add new data to it.