Structuring tabular data properly, and why tables are not a layout tool.
Tables are for presenting data in rows and columns. A well-structured table uses table, caption, thead, tbody and tfoot to group sections, tr for rows, th for header cells and td for data cells. The colspan and rowspan attributes let cells span multiple columns or rows, and the scope attribute on th (col or row) tells assistive technology which cells a header applies to.
Historically developers used tables to lay out entire pages, which is now considered bad practice because it mixes content with presentation, hurts accessibility and is hard to make responsive. Layout belongs to CSS Flexbox and Grid. Interviewers may ask how to make a wide table work on mobile (a horizontally scrollable wrapper is common), how to style borders with border-collapse, and why using th and caption matters for screen reader users navigating the data.
What you'll walk away knowing