A Perth man wanted to show that nice gestures go a long way when he left a note for two customers he overheard having a racist conversation at a table next to his.

Mr Hall's Facebook post featuring a picture of the receipt has received overwhelming support. ( Facebook: Jarred Wall )

Jarred Wall, 31, was having lunch with his fiancee and his two children at a Perth cafe when he listened to a pair of "elderly ladies" discussing Aboriginal people.

"The first part of the conversation started with basically one of them saying 'He got into power because of the colour of his skin' and it escalated from there," Mr Wall told ABC Local Radio.

In his post on Facebook, which has been shared 2,300 times, Mr Wall said "the conversation was less than distasteful with words like assimilation thrown around willy-nilly".

"I could have unleashed a tirade of abuse, but that wouldn't have helped," he said.

Instead, he did the opposite.

"I did something nice and bought them a pot of tea and left a little note on the receipt," he said.

"Maybe these ladies will be a little wiser and think before they speak. Hopefully there won't be a next time!" he posted, alongside #blacklivesmatter and #englishbreakfasttea.

Mr Wall's post has garnered more than 2,100 comments and more than 22,000 likes.

Fighting racism with positivity

Mr Wall said his intention with the note was to spark "a bit of thought in their minds" and to show that there were alternatives to dealing with conflict.

"It is hard to sit there when you can clearly hear something that does not sit well with you really, and I did not want to just sit there and say nothing, but I did not want to go over there and cause a scene," he said.

"Too often we see violence and negativity … and I thought how can I put a positive spin on this and show that there are other ways to deal with things?

"They probably did not realise that I was Aboriginal. I am sure they have had their own experiences and their own things that have happened in life that might have caused them to have such a view.

"But not every book is the same."

Mr Wall said after he left the receipt with a waiter he watched the ladies' reactions from afar.

"By that time the kids were getting a bit antsy so we went down to the park," he said.

"I could see the gist of how their reactions were."

Mr Wall said he was astonished at the overwhelming response to his post.

"I certainly did not expect it to spiral the way it has," he said.

"I hope they had a great day and a nice lunch; I just want people to think more before they speak.

"If I can bring some awareness in that respect, that is what I have tried to achieve I guess."