Is it ok to still use tables?

If you're presenting tabular data, it's fine to use tables. If you're doing layout, it's usually easier and lighter to use a few divs (and use a CSS framework like YUI or Blueprint) to do your work.

Yes. Tables are very good (even preferred) for tabular data.

For layout alone, there are newer and better options such as CSS Grid.

Tables work best for tabular data - if you are showing results of some query, like a list of customers or transactions or currency values, go ahead, you should be using tables.

What is bad is using tables for layout where the logical orger is not left-to-right i.e. if you have a navigation pane on the left, do you want to read the navigation before the content? probably not...

However if you have a form with labels and input fields do you want to read the label before the input control, yes, you probably do.

The reason for this is that screen readers and similar assistive technologies force this order on their users. also it is usually much harder to read the resultant HTML when you use tables for layout