The confusion of XHTML

Learning a day of XHTML, it feels simpler than c. However, there are some doubts. 1.XHTML seems to be able to write casually, basically do not encounter grammatical errors, but always feel that the things are not good to do; 2. The Nesting of table is not very clear. It's hard to do the same as the form. It feels like the form is the essence of XHTML, and it seems that any page can be written in table. In general, table has to be strengthened. We'll move to the neighborhood next week, so you don't have to waste your time on the bus. Keep working on it.