Bot= A character automated by a third party program to mine/gather/kill enemies over and over to attain large amounts of gold or materials to sell for Real Money on their illegal websites.

Grind/Mob Grinding = The act of killing the same monsters/enemies over and over to attain loot or experience points. Sometimes for hours on end, hence the "grind".

Add On = A LEGAL third party UI alteration that can be used for damage numbers, gathering node locations, and other quality of life improvements. Most of these are allowed by ZOS unless they provide some unfair advantage or alter the game. A more indepth description by ZOS can be found in their Terms you "agree" to when signing up

Normal Play = Not too sure on this one, perhaps referring to dungeons as Veteran Dungeons or Normal (low level) play dungeons. You got me on this one

I can help you with some of these.

Bot - or roBOT - An automated proces that controls an ingame character to do some specific things. Mostly used by leveling services or goldfarmers. They basically collect all kinds of materials to vendor, kill all types of mobs to level, or combining the two. They also have a typical and fixed behaviour pattern (always walking the same route, using the same skills and so on ..). You should report these every time you see them.

Grind- or Grinding : The process of doing the same thing over and over. You can 'grind' several things in the game. For example youi can grind crafting materials, like Iron Nodes, Jute Nodes, ....
It is tied in with Mob Grinding wich is a specific type of grinding, killing NPC's in order to level up, gain loot or gain money.
Another word for this would be farming, though there is a slight difference.

Normal play - well your guess is as good as mine with this. I think it might have something to do with the Veteran Mode (lvl 50+). Not sure though.

Add On - ADDition On the game. Eso supports the creation of little 3rd party modifications, like any Elder Scroll game before it (let's not argue ESO vs TES please). These little modifications allow you to change some aspects of the gamme, like the HUD, or Health bars , ... there are a lot of Addons. These are not made by the creators of ESO, and might stop working if the game evolves (patches & updates) when the Addon itself is not being maintained.

Hope this helps you !

Think I got it!! Thanks - fun game; but so much to it.