As per the HTML you have shared to click on the element you can use the following line of code :
driver.FindElement(By.XPath("//div[@class='ui-grid-selection-row-header-buttons ui-grid-icon-ok ng-scope']")).Click();
As the WebElement is an Angular WebElement you may require to induce WebDriverWait through either of the ways as follows :
Using Until :
WebDriverWait wait = new WebDriverWait(driver, TimeSpan.FromSeconds(10));
IWebElement myDynamicElement = wait.Until<IWebElement>(d => d.FindElement(By.XPath("//div[@class='ui-grid-selection-row-header-buttons ui-grid-icon-ok ng-scope']")));
myDynamicElement.Click();
Using wait.Until(ExpectedConditions.ElementIsClickable(By.by)) :
WebDriverWait wait = new WebDriverWait(driver, TimeSpan.FromSeconds(10));
IWebElement myDynamicElement = wait.wait.Until(ExpectedConditions.ElementIsClickable(By.XPath("//div[@class='ui-grid-selection-row-header-buttons ui-grid-icon-ok ng-scope']")));
myDynamicElement.Click();
Update :
As per the error you are seeing Element is not clickable at point (245, 310) see this discussion.