If someone is interested, when using a large screen, we can
have any table next to the primary one:

The buttons will work on Table 1 only.
However, editing Table 2 is possible.
We can have any number of tables on a screen.
This is all done with a template and a code in Table 1:
<div class="default-view">
<div class="form-body container-fluid">
<div class="row">
<!-- LEFT table -->
<div class="col-md-6">
<h5>Main Table</h5>
<div id="main-table" class="view-table"></div>
</div>
<!-- RIGHT table -->
<div class="col-md-6">
<h5>Any Table</h5>
<div id="extra-table" class="t_t2"></div>
</div>
</div>
</div>
.
.
function on_view_form_created(item) {
let t2 = task.t_t2.copy();
t2.open();
t2.create_table(item.view_form.find(".t_t2"));
}
For more tables, we need to add more code
and expand the template.
D.