ansible.azure.automation/roles/azure_rt/tasks/list.yml

---
- set_fact:
    tags_list: "{{ tags_list | default([]) |
    union([[tag.key,tag.value]|join(':')]) }}"
  loop: "{{ lookup('dict', rt.tags | default({})) }}"
  loop_control:
    loop_var: "tag"

- name: Get route table
  azure_rm_routetable_facts:
    ad_user: "{{ azure_ad_user | default(omit) }}"
    password: "{{ azure_password | default(omit) }}"
    subscription_id: "{{ azure_subscription_id | default(omit) }}"
    client_id: "{{ azure_client_id | default(omit) }}"
    secret: "{{ azure_secret | default(omit) }}"
    tenant: "{{ azure_tenant | default(omit) }}"
    resource_group: "{{ rt.resource_group }}"
    tags: "{{ tags_list | default(omit, true) }}"
    name: "{{ rt.name | default(omit, true) }}"
  register: azure_rt_facts

- name: Print route table
  debug:
    var: azure_rt_facts.route_tables
...