There are many options on Amazon for edge mounting brackets. We are dividing these into "Light Duty" and "Heavy Duty".
Light Duty have a 12mm (0.47") hole for mounting. Heavy duty has a 5/8" post to mount to.
For either, you need to think about the stress that puts on the table edge.
At this time we have not done any testing to determine maximum suggested loads for the light duty brackets. To mitigate that you may be able to use plates to distribute the load. The image to he right is a product example you may want to consdier with either light duty or heavy duty suggestions below if the table edge strenght is a concer.
Desk Edge Mounting - Light Duty
Desk Edge Mounting - Heavy Duty
https://www.amazon.com/dp/B0DKBFG9ZF?th=1
Plate system to distribute load.
The items we are referring to as Light Duty Brackets have a standardized 12 mm hole (0.47" hole). These were originally designed for light weight lamps lamps and microphones.
We need to adapt from that 12 mm / 0.47" hole to 1/2" or 3/4" EMT pipe or connector for a low cost solution.
A piece of 1/2" "all thread" just slips into that hole or may need to be lightly threaded in even though the hole has no threads. That all thread should then be secured with a locking bolt that is a main part of the given adapter. That creates a post we can then mount to.
This is the look you are trying to create...
For 1/2" EMT connection, use 1/2" all thread, a 1/2" washers, a piece of 1/2" pex for a bushing. Then use a 1/2" EMT coupling to mount the post to the base.
For 3/4" EMT connection, use 1/2" all thread, a 1/2" washers, and two half inch nuts for bushing. Then use a 3/4" EMT coupling to mount the post to the base.
https://www.amazon.com/Came-TV-C-Clamp-Thread-Exhibition-Lights/dp/B094MV5RQC
This comes with a 5/8" spud connector. That is specific to the lighting and sound industry.
The post is too large for a 1/2" connector however a 3/4" connector fits on with no bushings and works.
This particular bracket has a lot of 1/4" and 3/8" thread holoes, so there would be ways to mount smaller all thread to is and/or other post systems and then attach 1/2".
https://www.amazon.com/dp/B0BVZKKH9C/ref=sspa_dk_detail_5?pd_rd_i=B0BVZKKH9C&pd_rd_w=xzz4Z&content-id=amzn1.sym.f2f1cf8f-cab4-44dc-82ba-0ca811fb90cc&pf_rd_p=f2f1cf8f-cab4-44dc-82ba-0ca811fb90cc&pf_rd_r=RM1WHGTGGHQJD9X1267J&pd_rd_wg=NQMNg&pd_rd_r=8a002946-c903-42d5-b1f7-1ddbcba0667b&s=electronics&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWxfdGhlbWF0aWM&th=1