Open a blank tab in a browser using Selenium WebDriver for Mac & windows . Please check http://qaperspective.blogspot.in/2016/09/open-new-tab-using-Selenium-WebDriver.html

openNewTab.java

public void openNewTab() {
    String osName = System.getProperty("os.name").toLowerCase();
    if (osName.contains("win")) {
        driver.findElement(By.cssSelector("body")).sendKeys(Keys.CONTROL + "t");
    } else {
        driver.findElement(By.cssSelector("body")).sendKeys(Keys.COMMAND + "t");
    }
}