<aura:component implements="flexipage:availableForAllPageTypes" access="global" controller="dispalyAccountscontroller">
    
    <aura:handler name="init" value="{!this}" action="{!c.myAction}"/>
    <aura:attribute name="accounts" type="List" /> 
    
    <table class="slds-table slds-table--bordered slds-table--striped slds-table--cell-buffer slds-table--fixed-layout">
        <tr class="slds-text-heading--label">
            
            <th scope="col"><div class="slds-truncate" title="name">Name</div>  </th>
            <th scope="col"><div class="slds-truncate" title="industry">Industry</div></th>
            <th scope="col"><div class="slds-truncate" title="contacts">Contacts</div> </th>
            
        </tr>
        
        <aura:iteration items="{!v.accounts}" var="accs1" >
            
            <tr>  
                <th><div class="slds-truncate" title="{!accs1.Name}"><a href="javascript:void(0);">{!accs1.Name}</a></div>   </th>
                <th> <div class="slds-truncate" title="{!accs1.Industry}">{!accs1.Industry}</div>  </th>
                
                <table>
                    <aura:iteration items="{!accs1.Contacts}" var="con1" >
                        <tr>
                            <th><div class="slds-truncate" title="{!con1.LastName}">{!con1.LastName}</div></th>
                        </tr>
                    </aura:iteration>
                </table>
            </tr> 
            
        </aura:iteration> 
        
    </table>    
</aura:component>