Try it...

Pass all model  objects of the many2one field to the template.

then ...

<select>
    <t t-foreach="all_objects" t-as="each_objects">
        <option>
                <t t-esc="each_objects.name"/> 
          </option>
        </t>
</select>    

Does anybody know how to "Pass all model  objects of the many2one field to the template.", see answer of "Odoo developer". I could not find an easy way. I could grap the model in the controller via env() and then try to fetch all records in a for loop or something like that but there must be a simpler "odoonic" way to do this, I guess.

(As the questions is old, I am using Odoo 11)

(I would have done a comment but I am  not allowed)

Thanks 

Ok, figured it out myself:

put this in the controller

all_objects = request.env['model.name'].search([])

values = {

"some_values": some_values,
"all_objects": all_objects

}

return request.render(template_name, values)