why TDs display within a TR displays in the same line?

Question

TD is a block element,

but displays like inline,say,several TDs within a TR display in the same line,

why?

Answer 1

TD's are actually not technically "block" elements. Have a look at the CSS display property. Cells are technically of type "table-cell" and they are a special case.

There is also another type of display called "inline-block" which can be useful.

Answer 2

Because they are for tabular data.