How to always display two types of rows in angular material table

Is there a possibility of always showing the extra detail rows after each master row without having to click each master row to reveal the detail?

You can always create a custom table, providing rows as dense with details as you want.

Starting from the example of Expandable rows, I edited the code taking the logic of showing and hiding the details away, so the detail are always visibile:

<table mat-table
       [dataSource]="dataSource" multiTemplateDataRows
       class="mat-elevation-z8">
  <ng-container matColumnDef="{{column}}" *ngFor="let column of columnsToDisplay">
    <th mat-header-cell *matHeaderCellDef> {{column}} </th>
    <td mat-cell *matCellDef="let element"> {{element[column]}} </td>
  </ng-container>

  <!-- Expanded Content Column - The detail row is made up of this one column that spans across all columns -->
  <ng-container matColumnDef="expandedDetail">
    <td mat-cell *matCellDef="let element" [attr.colspan]="columnsToDisplay.length">
      <div class="example-element-detail expanded">
        <div class="example-element-diagram">
          <div class="example-element-position"> {{element.position}} </div>
          <div class="example-element-symbol"> {{element.symbol}} </div>
          <div class="example-element-name"> {{element.name}} </div>
          <div class="example-element-weight"> {{element.weight}} </div>
        </div>
        <div class="example-element-description">
          {{element.description}}
          <span class="example-element-description-attribution"> -- Wikipedia </span>
        </div>
      </div>
    </td>
  </ng-container>

  <tr mat-header-row *matHeaderRowDef="columnsToDisplay"></tr>
  <tr mat-row *matRowDef="let element; columns: columnsToDisplay;"
      class="example-element-row"
      [class.example-expanded-row]="expandedElement === element">
  </tr>
  <tr mat-row *matRowDef="let row; columns: ['expandedDetail']" class="example-detail-row"></tr>
</table>

https://stackblitz.com/edit/angular-rgyuhs?embed=1&file=app/table-expandable-rows-example.html

Observe that the div with the class "example-element-detail" also have "expanded" class (which of course could be any other name) and all the content defined in the "expandedDetail" will always be displayed in tr "example-detail-row"