Slack webhook html table

No, I don't believe there's any way to draw a table in a Slack message.

Here are other available options for formatting Slack messages: https://api.slack.com/docs/formatting.

You can now do simple two column tables in slack using the "fields" layout block.

You can do two column table:

[
   {
        "type": "section",
        "fields": [
            {
                "type": "mrkdwn",
                "text": "*Name*"
            },
            {
                "type": "mrkdwn",
                "text": "*Email*"
            },
            {
                "type": "plain_text",
                "text": "Jeff Henderson",
                "emoji": true
            },
            {
                "type": "mrkdwn",
                "text": "[email protected]"
            },
            {
                "type": "plain_text",
                "text": "Anne Polin",
                "emoji": true
            },
            {
                "type": "mrkdwn",
                "text": "[email protected]"
            }

        ]
    }
]

Giving you:

Or go field style:

[
    {
        "type": "section",
        "fields": [
            {
                "type": "plain_text",
                "text": "Name",
                "emoji": true
            },
            {
                "type": "mrkdwn",
                "text": "*Jeff Henderson*"
            },
            {
                "type": "plain_text",
                "text": "Email",
                "emoji": true
            },
            {
                "type": "mrkdwn",
                "text": "[email protected]"
            },
            {
                "type": "plain_text",
                "text": "Mobile Phone",
                "emoji": true
            },
            {
                "type": "mrkdwn",
                "text": "0451000000"
            },
            {
                "type": "plain_text",
                "text": "Work Phone",
                "emoji": true
            },
            {
                "type": "mrkdwn",
                "text": "94550000"
            }

        ]
    }
]

Will yield:

I have opened a ticket to Slack support asking if Slack's Incoming Webhook message supports table of any form (HTML or Markdown).

The official answer is that Slack messages do not support tables.

They suggest to generate a table and post it as an image.

They also said that they will add it to their backlog.