As a noun 盘 = 盘儿 = 盘子.

盘 is dish,tray,tray in China,the name of one Character things sometimes add a 子 behind,like 裤子（pants） 鞋子（shoes） 碟子（small plate） 本子（notebook） 脑子（brain） in North of China,we always add 儿 behind the words,if you ever come to Beijing，you will hear they say 哪儿,杯儿，碗儿，脑儿... so you can treat as it is different language habit between north of China and South of China,in north use 儿，in south use 子 of course,儿 also means son,your parents and eldership can call you name+儿 hope that could help you:)

Agree with Jack. 盘儿 is like a name,I guess. in Chinese ancient parents call their child first name+儿. e.g. Someone‘s called 李斌，his parents or grandparents will call him 斌儿. Here 盘儿 maybe his first name is 盘. Just guessing. 盘子 is plate ,tray, dish.

盘儿 may be used for name, i.e. some girls may be named as 盘儿。 Otherwise, it's rarely used like this. 盘子 means plate tray or dish. It‘s a noun.