Is this guy asking me out on a date, or just to a casual meal?

So I met this guy at work, who seemed interesting but he still was a customer. When I ring people up, I ask questions about themselves and lots of other things. This one particular person was attending a university as a culinary student from China. We talked for a bit and then he left with his purchase. Within little more than a week, he returned, and asked if we could chat sometime, so I gave him my facebook rather then hand out my number to a random guy I only met once before. I just saw that he had sent me a few message, saying hello, and such and he said he made a slight blunder with how he said things. The message goes as follows:

"Sorry, I did a culture misunderstanding. I talked with my American friend and I found that my word made you confused. In fact, I would like to invite you to have a meal. Have a good night"

I'm not sure what he meant by 'culture misunderstanding'. I really don't have much of any interest in getting into a relationship or serious dating. I don't know what I should say, or if he is just interested in talking more outside of my workplace. In any case, I don't want to be mean or misunderstand if he has no interest in dating. What do you think I should say in responding to this message.