Sorry to hear you only had 10 peas? How many did you plant? Did they all sprout? or something like slugs consumed them when they were young and tasty?
tomatoes are still growing so you should be getting more same for beans.Beans should be picked up young if you let them go too far the entire plant stops producing concentrating its energy on seed production so maybe that's the case. Its important for you to know why such poor results?It will be easier to plan the garden when you know why you are only getting few peas, beans etc.
You may consider to prune your maple a bit to allow more light ( it will re grow )
Most important for you is really to find out why such poor results.Our Vancouver summer has been incredible and most people have abundance of veggies right now.

It's difficult to speculate on why you've had such poor performance from your veggie garden, but I'd surmise lack of sunlight and less than ideal soil conditions are contributing. Most vegetables prefer 6-8 hours (or more) of full sun to grow and produce well - shading from a large tree canopy during the height of the growing season can certainly have an adverse impact. Then too there is the question of how close the maple is to the planting area - most maples produce very widespreading, close to the soil surface root systems that make it very difficult for smaller plants nearby to compete for nutrients and soil moisture. Sometimes it is possible to overcome this situation by planting in raised beds but if too close to the maple, the tree roots will invade the raised beds as well.

Is it possible to relocate your vegetable garden to an area that is open to more sun and well away from any large trees? You will get much better results.