How to adjust the space for each row in the table?

I am not good at css, no good at all, I need to decrease the space between each row, please see my website

As you can see, there are 6 rows and each row has 4 images on the home page.

There is also a price/location row for each row of images

The images row didn’t use all the space, I want to decrease it but I don’t know which css element I should change.

Can someone point it out for me?

Thank you very much