Translation:The strong pupils are carrying the table.
What was the other sentence you saw?
Presumably that sentence didn't have the article "die" before it. Adjectives conjugate differently depending on the article before them, or whether there is an article at all. So you write "Die starken Kinder tragen ...," but with no article it would be just "Starke Kinder tragen ... ."
Here are some conjugation charts.
This is ten months late but. . .
"Studenten" in the example you cite is nominative and there is no article, thus "stark" uses strong declension. The sentence from the discussion has a definite article "die", therefore "stark" uses mixed declension in it.
There is also "weak declension". Sadly, I'm not kidding.
Here's a link to the German declension wiki.