Provide lots of throwing and tossing and dropping activities during non-meal times. A heap of pebbles and a pond are great. Balls, cleanup time putting toys in a bin together, sensory bins (that you don't mind cleaning up after... I always minded so I never did this
) and the like.
I chose a cupholder spot on DD's tray and told her it was the spot for things she did not want to eat. She did pretty well with "if you don't want it, put in in the no thanks spot."
Let go of how much you think she needs to eat. They really don't need much and letting them choose and accepting that is hugely important. Offer some food during play if your family is ok with that. Mine did really well with picking at a little muffin tin with a few snacks in it - cubed leftover meat, fat cheese shreds, diced frozen (still cold) veggies, cereals, etc. It took a lot of pressure off mealtimes.