Hi Kevin,
Honestly, I'm not certain if this is on the Web App Builder roadmap or not at this time.
However, as I'm sure you're aware, Web App Builder does have a "Query" widget that can be used as a "Select by Attributes" tool depending on what you're trying to do.
If you're trying to see only the query results in the attribute table, then check the option to create an operational layer, navigate to your attribute table via the arrow at the bottom of your map, and the new layer with only the selected records should be one of the tab options in there. Alternatively, if for some reason it is not there, open your layer list, hit the drop down arrow next to the operational layer, and click "Show in Attribute Table".
If you're interested in editing a selection then our "Batch Editor" widget can be used. This should allow you to edit using "Select by Location" or a "Select by Feature" functionality. This widget can be found here in our open github repository.
As far as *directly* addressing your question - widgets in Web app Builder will have the ability to communicate with each other in the near future. This would presumably mean that the query widget would be able to directly communicate with the attribute table widget to reflect your selection directly.
Hope that helps.
Thanks,
Hunter