How to Get More Accessory Slots in Terraria - Game Voyagers
In my opinion, even one more accessory slot would make the game too easy "as-is". Terraria would need rebalancing. I don't think it is good idea.
Amazon.com : HIGOO 11mm Dovetail to 20mm Picatinny/Weaver Low ...
These more secure and stable tool board accessories are for use with the slots found in Wall Control Metal Pegboard tool board panels only. ...
Informational Accessories - Official Terraria Wiki
In Terraria, accessories are items that can be equipped in the accessory slots below your armor. These include the following: Amulets Bells Earmuffs Headbands ...