I can't find answer anywhere, can somebody tell me why and how to avoid these little dots/holes when I spackle.
I also including the pic of the compound I'm using.
There have got to be many ways to minimize the bubbles. These kind of problems you deal with when finishing drywall require a certain amount of skill that, for me, comes only with experience. That said, I have a few ideas:
Actually, @Edwin gave you a good answer. I'll add a bit to it. The bubbles are usually from not mixing the mud well enough or not applying it with enough pressure. It is not unusual to see lots of small bubbles on the first coat. The second coat is going to be thinner and applied with a bit more pressure and wider knife or trowel than the first. Here's a little trick for your third or final coats of mud. Mix a small amount of water and Ivory dish soap into your mud and mix well. It will glide on like soft butter and be as smooth as a baby's bottom!! Also, practice makes perfect, mudding takes a lot of practice, so hang in there.
You are getting these because the compound going on is too thick.
My drywall guys start with a small bucket of powder and water and mix to the consistency of pancake syrup and then add the premixed stuff in. Basically to the point where it barely doesn't drive you nuts. It will make a mess no doubt because you will have drop everywhere. But this allows for smaller/wider coats that will require almost no sanding and we hardly ever have bubbling issues.
The fact is the premixed compound out of the jar will start drying so fast that the air will escape during the initial drying process. They sell it this way because it is more usable and you can always add moisture but much harder to take it out.
I have always had air bubble problems when patching over a painted surface. They occur in each succeeding coat, but a little less. I have found that sanding the first coat and then wiping thoroughly with a wet sponge seems to fill in the bubbles so they don't appear in succeeding coats near as bad.