I can't seem to stop thinking about this thread. The word Lazy is so loaded. I know you don't mean it that way, but it is full of connotations that are, especially in the societies of the Global North, considered socially unacceptable and deviant.
He really doesn't seem to be that different than any other six year old I know, especially one with a father who is, as your sig points out, a gamer. I wouldn't be too quick to slap any labels on him. I might take him for a physio-therapist exam to see how he might be able to (in an ENJOYABLE way) improve his gross and fine motor skills (my DS needs help with these too, but his Gran is an occupational therapist and has given us some great strategies that feel too much like play for DS to realize he is developing any skills, within weeks he was right where his teachers thought he shouold be), but I'd be very wary of fishing for a diagnosis which doctors, especially in the States, are all too happy to dole out. I'd be particularly careful of diagnoses that imply heavily medicating a still growing child with psychotropic drugs. There is nothing you have described, Minkajane, that seems particularly odd or abnormal to me. I know it is hard to get inside the mind of a six year old boy, but as a teacher I have read quite a lot about childhood devlopment, and both physically and educationally your son does NOT sound off the scale of normal.
Kids take a long time to eat. My DS usually takes about an hour to eat his dinner, and he takes breaks in the middle to hug people, to tell a story. Actually when you think about it. it's not only MUCH healthier to eat this way, it is also a very nice time to bond, to s l o w d o w n and talk to your kids about thier day. We used to fight it, now we embrace it and realize it's one of the best times of the day...we just have to be careful to build in the time...I typically get home and start dinner immediately, or ask our housekeeper or DH to throw some stuff in a crockpot for me. It's not to say we never get annoyed but that is MY issue, not his.
Kids space out. Their brains (like their tummies) need more time to disgest information and at this age? They are absorbing information lightening fast and so every now and then they drop out to process. It's totally normal. Most first grade teachers I know build processing time into their daily schedules because kids this age NEED this time to just be quiet and think. FWIW, it is during these moments that DS comes up with some of his most ingeneous ideas. He's not being lazy, he's being reflective. Even if you ask him what he's thinking and he says "nothing" what that really means is EVERYTHING.
Kids do talk incessantly when they are excited about something. Almost every child I know does this, and it is SO frustrating. But they will calm down eventually. And you can't tell me you seriously cared about the movie Tangled (if you did, perhaps try watching it alone first, and then with him -- I do this when I actually want to see the film). It's a kids film. The whole point of you watching a kids film (correct me if I'm wrong) is to BOND with your kid, not to watch a film. Really. It's to share a moment and build a memory, no? So, as gently as I can, I am suggesting you chill out a little and enjoy the talking. He's opening up to you. Let him.
The spotting stuff on the floor is also SUPER irritating, but as far as I can tell, normal, and boys are particularly bad at spotting details (they have more frenetic energy than girls as a general rule) and they see the world from a very different perspective. It's one of the reasons their art work tends to be (and obviously this gender separation is not 100% accurate, it's just tendencies) chaotic and they color out of the lines so much longer than most girls. It's the way they view the world. It helps me if I get down on his level (I forget sometimes that being three feet taller gives me a better vantage point for things) and then if I narrow the viewing circle..."Look between the coffee table and the sofa, do you see it now? No? Look between the sofa and the throw rug, do you see it now?..." and so on. Another thing that has helped has been playing a LOT of "I spy", on the bus, on the sidewalk, in the park, at the supermarket, everywhere! and also those spot the difference games. It's so much fun for him to solve the puzzle and it helps train his eye for detail. remember that grown up have learned to control their retina and focus much more specifically than children.
Lazy is a really unkind word in my point of view, and I gently suggest that you rephrase and reshape your perspective on your son and consider that he is just six and may see the world in a different way from you.
ETA: I also just noticed that you are near the end of your pregnancy...this may be affecting your patience levels and he might be resisting you in fear of the coming baby...he may be testing your rejection tolerance to see if this baby is going to replace him or make less time and less love for him. You may want to address thyis emotional fear before you push too hard on finding out "what's wrong with him?" Kids will internalize these feelings, especially if they sense that baby is obviously accepted and happily so by the family. They may not even realize they feel anxiety about it, but if you think about it, anxiety must be inevitable. This is HUGE life change for him, I think you should tread gently and allow him to express this fear how he needs to.