<?php
     echo GridView::widget([
         'dataProvider' => $provider,
         'options' => ['style' => 'max-height:30px;',
                                    'max-width:10px;',
                      ],
         'columns' => [
             ['class' => 'yiigridSerialColumn',
                 'contentOptions'=>['style'=>'width: 30px;']],
             //subject
             [
                 'attribute' => 'subject',
                 'format' => 'text',

                 'label' => 'Subject',
                 'contentOptions'=>[
                     'style'=>
                         ['width: 10px;',],

                 ]
             ],
             //body
             [
                 'attribute' => 'body',
                 'format' => 'text',
                 'label' => 'Body',
                 'contentOptions'=>['style'=> 'max-width: 100px;', 'height: 100px']
             ],
             ['class' => 'yiigridActionColumn',
                 'controller'=>null,
                 'header'=>'Action',
                 'headerOptions' => ['width' => '70'],
             ],
         ],
         'tableOptions' =>['class' => 'table table-striped table-bordered'],
     ]);
?>