table.row_class.column_class

table tr.some_row_class td.some_column_class`

WebElement htmltable=driver.findElement(By.xpath("//*[@id='main']/table[1]/tbody"));

List<WebElement> rows=htmltable.findElements(By.tagName("tr"));

for(int rnum=0;rnum<rows.size();rnum++)

{

    List<WebElement> columns=rows.get(rnum).findElements(By.tagName("th"));

    System.out.println("Number of columns:"+columns.size());

    for(int cnum=0;cnum<columns.size();cnum++)

    {

        System.out.println(columns.get(cnum).getText());

    }

}