export type OwnerInputType = {
    name: string;
    address: string;
}

export type AccountType = {
    'id': string;
    'description': string;
    'ownerId' : string;
    'type': string;
}

import { AccountType } from './accountType';
 
export type OwnerType = {
    'id': string;
    'name': string;
    'address': string;
    'accounts': AccountType[];
}

ng g s graphql

import { Injectable } from '@angular/core';
import { Apollo } from 'apollo-angular';
import gql from 'graphql-tag';

@Injectable({
  providedIn: 'root'
})
export class GraphqlService {

  constructor(private apollo: Apollo) { }
  
}

  public getOwners = () => {
    return this.apollo.query({
      query: gql`query getOwners{
      owners{
        id,
        name,
        address,
        accounts{
          id,
          description,
          type
        }
      }
    }`
    });
  }

export class AppComponent implements OnInit {

  public owners: OwnerType[];
  public loading = true;

  constructor(private graphQLService: GraphqlService) { }

  ngOnInit() {
    this.graphQLService.getOwners().subscribe(result => {
      this.owners = result.data["owners"] as OwnerType[];
      this.loading = result.loading;
    });
  }
}

<div>
    <div *ngIf="!this.loading">
        <table>
            <thead>
                <tr>
                    <th>
                        #
                    </th>
                    <th>
                        نام و نام خانوادگی
                    </th>
                    <th>
                        آدرس
                    </th>
                </tr>
            </thead>

            <tbody>
                <ng-container *ngFor="let item of this.owners;let idx=index" [ngTemplateOutlet]="innertable"
                    [ngTemplateOutletContext]="{item:item, index:idx}"></ng-container>
            </tbody>

        </table>
    </div>
    <div *ngIf="this.loading">
        <p>
            در حال بارگذاری لیست ...
        </p>
    </div>
</div>


<ng-template #innertable let-item="item" let-idx="index">
    <tr>
        <td>{{idx+1}}</td>
        <td>{{item.name}}</td>
        <td>{{item.address}}</td>
    </tr>
    <tr *ngIf="this.item.accounts && this.item.accounts.length > 0">
        <td colspan="4">
            <div>
                <p>Accounts</p>
            </div>
            <div>
                <table>
                    <thead>
                        <tr>
                            <th>#</th>
                            <th>نوع</th>
                            <th>توضیحات</th>
                        </tr>
                    </thead>
                    <tbody>
                        <tr *ngFor="let innerItem of this.item.accounts;let innerIndex=index">
                            <td>
                                {{innerIndex+1}}
                            </td>
                            <td>
                                {{innerItem.type}}
                            </td>
                            <td>
                                {{innerItem.description}}
                            </td>
                        </tr>
                    </tbody>
                </table>
            </div>
        </td>
    </tr>
</ng-template>

dotnet restore
dotnet run

ng serve

  public getOwners = () => {
    return this.apollo.watchQuery<any>({
      query: gql`query getOwners{
        owners{
          id,
          name,
          address,
          accounts{
            id,
            description,
            type
          }
        }
      }`
    })
  }

  public getOwner = (id) => {
    return this.apollo.query({
      query: gql`query getOwner($ownerID: ID!){
      owner(ownerId: $ownerID){
        id,
        name,
        address,
        accounts{
          id,
          description,
          type
        }
      }
    }`,
      variables: { ownerID: id }
    })
  }

  public createOwner = (ownerToCreate: OwnerInputType) => {
    return this.apollo.mutate({
      mutation: gql`mutation($owner: ownerInput!){
        createOwner(owner: $owner){
          id,
          name,
          address
        }
      }`,
      variables: { owner: ownerToCreate }
    })
  }

  public updateOwner = (ownerToUpdate: OwnerInputType, id: string) => {
    return this.apollo.mutate({
      mutation: gql`mutation($owner: ownerInput!, $ownerId: ID!){
        updateOwner(owner: $owner, ownerId: $ownerId){
          id,
          name,
          address
        }
      }`,
      variables: { owner: ownerToUpdate, ownerId: id }
    })
  }

  public deleteOwner = (id: string) => {
    return this.apollo.mutate({
      mutation: gql`mutation($ownerId: ID!){
        deleteOwner(ownerId: $ownerId)
       }`,
      variables: { ownerId: id }
    })
  }