public void MoveStandaloneTable( 
   StandaloneTable table,
   CompositeLayerWithTables targetLayer,
   int position
)

//get the first group layer that has at least one table
var grp_layer = MapView.Active.Map.GetLayersAsFlattenedList()
  .OfType<GroupLayer>().First(g => g.StandaloneTables.Count > 0);
var map = MapView.Active.Map;//assumes non-null
QueuedTask.Run(() =>
{
  //move the first table to the bottom of the container
  grp_layer.MoveStandaloneTable(grp_layer.StandaloneTables.First(), -1);

  //move the last table in the map standalone tables to a group
  //layer and place it at position 3. If 3 is invalid, the table
  //will be placed at the bottom of the target container
  //assumes the map has at least one standalone table...
  var table = map.StandaloneTables.Last();
  map.MoveStandaloneTable(table, grp_layer, 3);

  //move a table from a group layer to the map standalone tables
  //collection - assumes a table called 'Earthquakes' exists
  var table2 = grp_layer.FindStandaloneTables("Earthquakes").First();
  //move to the map container
  map.MoveStandaloneTable(table2, 0);//will be placed at the top
});