Hi,
Add the code below to your custom css option.
.wishlist_table .add_to_cart.button, .yith-wcwl-add-button a.add_to_wishlist, .yith-wcwl-popup-button a.add_to_wishlist, .wishlist_table a.ask-an-estimate-button, .wishlist-title a.show-title-form, .hidden-title-form a.hide-title-form, .woocommerce .yith-wcwl-wishlist-new button, .wishlist_manage_table a.create-new-wishlist, .wishlist_manage_table button.submit-wishlist-changes, .yith-wcwl-wishlist-search-form button.wishlist-search-button {
margin: 0px!important;
}
Hope it helps.
-Rui