When you enable check section from column tab, than your customer are able to select one or multiple product by clicking the checkbox.
By default no product are selected but if you want that all product should be selected automatically when the table load you can do that. There is a section “Checkbox Auto Check on Table Load (Enable/Disable)” in “Basic” tab.
Also you can change those text "Add to Cart" and "All Check/Unchecked" from there.
