"do tell" meaning in English

{
  "etymology_text": "Abbreviation of the hortative phrase “please do tell me more.”",
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "phrase"
      },
      "expansion": "do tell",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "phrase",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English entries with language name categories using raw markup",
          "parents": [
            "Entries with language name categories using raw markup",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms with non-redundant non-automated sortkeys",
          "parents": [
            "Terms with non-redundant non-automated sortkeys",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "You say you're an astronaut? Do tell.",
          "type": "example"
        }
      ],
      "glosses": [
        "An idiomatic expression of mild interest or surprise within a conversational context."
      ],
      "id": "en-do_tell-en-phrase-7NyZ8byc",
      "synonyms": [
        {
          "tags": [
            "archaic"
          ],
          "word": "pray tell"
        },
        {
          "word": "oh really"
        },
        {
          "word": "I declare"
        },
        {
          "word": "you don't say"
        },
        {
          "word": "is that so"
        }
      ]
    }
  ],
  "word": "do tell"
}

{
  "etymology_text": "Abbreviation of the hortative phrase “please do tell me more.”",
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "phrase"
      },
      "expansion": "do tell",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "phrase",
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English entries with language name categories using raw markup",
        "English interjections",
        "English lemmas",
        "English multiword terms",
        "English phrases",
        "English terms with non-redundant non-automated sortkeys",
        "English terms with usage examples"
      ],
      "examples": [
        {
          "text": "You say you're an astronaut? Do tell.",
          "type": "example"
        }
      ],
      "glosses": [
        "An idiomatic expression of mild interest or surprise within a conversational context."
      ],
      "synonyms": [
        {
          "tags": [
            "archaic"
          ],
          "word": "pray tell"
        },
        {
          "word": "oh really"
        },
        {
          "word": "I declare"
        },
        {
          "word": "you don't say"
        },
        {
          "word": "is that so"
        }
      ]
    }
  ],
  "word": "do tell"
}