Usually left-aligned looks much better than center-aligned, but in this case not necessarily. Here, left-aligned looks proper but somewhat crowded and much of the white space that would make the page look clean is lost to one side. The center-aligned is a but funky but I think the white space makes it look more inviting and improves readability.
Also, as already mentioned, if changing one of the thoughts table, they all ought to be changed. For something like this where one change actually obligates making the change in multiple places, I would create a sandbox page under my user page, copy the table, and do all the changes and experimentation I want, settle on what looks best, and maybe get some input from others.
All that said, you could still be right, but it's hard to tell when it doesn't have the the coloration and row dividers.
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