Hello,
Remember, PHP relies on (X)HTML for screen output, so it can be said that whatever HTML doesn't support is generally not supported by PHP. However, you can mock DBGrid (or mostly anything you see in standalone applications, such as tabs, tree structures, etc), and displaying query result row-by-row, field-by-field and make them all editable is certainly doable with PHP (get the data-to-edit and run a loop to place them in a table with textboxes, etc, in each cell).
One limitation to note, however, is that PHP is not strongly event-driven, so you need to somehow reload("submit") the page in order to save the changes made to the grid.
You might also want to take a look at ASP.NET, which I heard is event-driven. HTH.