Thanks for your post, you can set TextStyle to show the text in each feature, please check the below code snippet:
TabFeatureLayer tabFeatureLayer = new TabFeatureLayer(@"Test.TAB");
tabFeatureLayer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
tabFeatureLayer.ZoomLevelSet.ZoomLevel01.DefaultTextStyle = TextStyles.CreateSimpleTextStyle("PLACENAME", "Arial", 12, DrawingFontStyles.Regular, GeoColor.StandardColors.Black, GeoColor.FromArgb(100, GeoColor.SimpleColors.Green), 2, 0, -8);
For Symbol object, sorry but to limit the Tab file size our products cannot support reading information of Symbol from Tab file. You can use the Marker to replace the Symbol to achieve your require, but you need read the Symbol information with your own logic. Also you can raise a professional service for us to check this feature.
Sorry for the inconvenience.