You can use emoji in our plugin, but to specify required emoji in HTML using the codepoint, you have to modify the value. Add the &#x characters, remove the U+1 from the beginning of the codepoint, and just add the remaining digits from the codepoint as part of any text element.
For the hamburger emoji, the codepoint is U+1F354.
Here is the code for hamburger emoji, which you should add in Table Editor to make it work: <p>🍔</p>
Also, you can use this website to find required emoji and simply copy and paste it to html text: https://emojipedia.org/
Unfortunately none of the train emojis seem to be recognised, even though they do work on Google Sheets and can be pulled in from there on WordPress. I have tried using <p>🚅</p> and <p>🛯</p> and <p>🚈</p> and <p>🚄</p>. When I tried your hamburger emoji code the effect was the same; in Preview the row had disappeared, even though I could see the emoji in editor.
Looks like there are some issues on your website, because I used the same code <p>🚄</p> on my test server and train emoji is showing both on front and backpage.
Please, look these screenshots: http://prntscr.com/k552yr – for frontpage; http://prntscr.com/k553sn – for table editor.
Can you try to add required emoji simply to worpdress text editor on a new page? Does it show properly?
We should identify where exactly is that issue – on your website at all, or only in our plugin on your website.