When you enable the check section from the column tab, then your customer is able to select one or multiple products by clicking the checkbox.
By default no products are selected but if you want that all products 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.
