In some Asian countries, eating with both hands might be considered rude or not appropriate but in the country like Thailand, Thai people use spoon on right hand and fork on the left -- both and together. Chopsticks somehow adopted from China and used for eating single dish noodles.
Single Dish
I'd say single dish is great choice for "singles"or two-people families, good choice for lunch on busy days or even dinner for extremely busy days. (Single dish is for everyone, duh!) A Thai single dish is a complete meal in one dish that fills you up which always includes either rice or noodle. A dish contains rice/noodle, meat and vegetable -- all in one dish -- served with no other side dishes just a little bowl of fish sauce dip (prik-nam-pla) to add taste.
We all love the moment of joy when eating good food with many others, friends or families --Thai people too... I do! A Thai full meal is not a single main course with side dishes but a meal that consists of many various courses containing a variety of curry or soup, stir-fried dish, deep fried or steamed dish and dip or spicy salad served with fresh and steamed vegetables. All dishes are shared and enjoyed together (each dish has it own spoon for sharing called 'middle spoon'). Each person has one own plate, when ready, steamy hot rice is served one each plates. And the joyfully moment begins! We use the middle spoon to take a bit (spoonful) of the course we want, put it on to our own plate, leave the middle spoon at the same dish it is taken from originally. Then we eat that bit of food together with the rice at once, meaning... we use the fork (left hand) to scrape food and rice on to the spoon (right hand) half and half. That's one bite. And that's how we enjoy each course - bit by bit.
Unlike the western style, soup is eaten with other dishes, not before. Soup is set in one big bowl and a bigger type of middle spoon provided for sharing. Each person has one own much smaller bowl. Same thing, we use the middle spoon, take the soup only a couple of spoonful (considering we all share, leave some for everyone to enjoy too). And the concept of having at least one soup dish for each full meal is that the soup helps clearing throat as rice can be very dry. Or some courses taste really 'sharp', and soup helps soothing tongues (haha... sounds funny but it works really nicely). I remember growing up being taught all the time not to drink while eating. Though drink is served anyway, we don't drink before or during meal.