My 9mo is BLW and currently eats off his high chair tray or from the table.
The only other thing we've tried - tommee tippee magic mat with plate - is an intermittent success. If it's a meal he loves then he is fine, but if he's a bit disinterested in the food then he can pull the plate straight off the mat despite it supposedly being designed to stop that and throws food and plate everywhere.
When should we introduce a spoon/fork? As with all things BLW, I guess it's for fun at first and then he'll gradually get used to it. When can I expect him to start using a spoon/fork himself?