Why did I get concrete honeycombing
If you want no holes, you have to compact it, easiest is with vibration but that needs a special tool. Or you can poke a stick in and out of it for a while. I've had great success by fastening a bit of wood plank on the business end of a vibrating sander and using that as a vibrating float.
Don't worry though, you're not building a suspension bridge, it's not going to come apart. If it was a thin load-bearing shape like a slab, then it would be worrying to have it &quot;pre-fractured&quot; like that, but this is a big chunky block whose only job is to be heavy and take a few screw anchors.
If the holes are an aesthetic problem, you can always cover it with a mortar made with a mix of fine sand and cement, apply like plaster.
For next time:
Since this is not a load bearing item like a slab, you can put in a bit too much water so it flows better. It will be a bit weaker, and have a bit more cracks, none of it matter for what is basically a concrete boat anchor. Or you could mix in some concrete plasticizer, which makes it a lot easier to work with without compromise in solidity, but that's a bit expensive and way overkill for this job.