I'm not sure what are you looking for in responses, or where you encountered difficulty in solving, so here's my few grain of salt in this.
If you are splitting the text separated by
commas only:
Code
$sentences = explode(',', $text);
What problem I see here, is that your text cannot contain a single comma since the comma symbol is used as a delimiter, which 9/10 of the chance won't work nicely. I use multiple commas in a single sentence at times.
Then, if you want to join up the $sentences array into a subgroup, you can group them up further using array_chunk function
Then I think it's best not to work with <td>, those are for excel kind of use for storing hard statistical data use only where you need to search value by columns. Secondary, they are not responsive to screen sizes.
By way of splitting them into 2 columns, you have few choices to do this.
1. Using Bootstrap
Code
<div class='row'><div class='col-xs-12 col-sm-6'>".implode("</div><div class='col-xs-12 col-sm-6'>", $sentences)."</div></div>
Code
.grid {
display: grid;
grid-template-columns: repeat(2, 1fr);
gap:15px;
}
<div class="grid"><div>".implode("</div><div>", $sentences)."</div></div>
If you do not want to limit to 2 columns, you can go for a more linear
flex type of div container. It is when we need content to stack downwards to next row automatically once the content goes off screen.