You can use the table theme type to do this. In your build section, return a render array that includes this:

return [
  '#type' => 'table',
  '#header' => $header,
  '#rows' => $rows,
];

Where header is an array of strings and rows is an array of row value arrays.

You can use the table theme type to do this. In your build section, return a render array that includes this:

return [
  '#type' => 'table',
  '#header' => $header,
  '#rows' => $rows,
];

Where header is an array of strings and rows is an array of row value arrays.

Some reference items I found:

New render element #type 'table'

Render arrays