Need or Don't Need? 我需要它吗？

I have a meet up with a business contact today. We talked about each other's work, life and subject of death.
今天，我约了一位朋友互谈彼此的工作，生活和对死亡课题的看法。

As a Chinese, we have the tradition of worshiping our ancestors. One of the practice is to worship the ancestral tablet. Her question is: Is it a must to have a tablet for oneself?
身为华人，很多（华人）都有祭拜祖先的习惯。其中之一的做法，就是拜祖先神主（牌）。朋友的疑问是：神祖牌是不是一个必需品？

Why would she have such a question? It is because some of her married friends have no children. This question confuses them: If I have passed on without a children, who will come to worship me through my ancestral tablet?
为何她会有如此的疑问呢？那是因为她身边的一些朋友们并没有孩子。这问题很困惑他们：当自己离开人世以后，谁会来拜祭我？那，到底我是需要或不需要（神主牌）呢？

Besides set up a ancrestral tablet at home, nowaday Singaporeans are more incline to own tablets or offering worhip in the temple or columbarium. Instead of confusing, why not we understand the purpose of its existence first? I believe after watching the below video, you will naturally have an answer.
神主牌不止可以供奉在家，现代新加坡人也比较倾向于供奉在庙与骨灰殿。与其困惑，不如我们来听听看净空法师解释神主牌存在的意义。我相信在观赏之后，你很自然的就会得到一个答案。

This video is an useful reference, please watch from 27:47 to 29:05 minute.
敬请收看以下从27:47至29:05的视频。

Some examples of ancestral tablet from different temples/columbariums, in both traditional and contemporary designs.
这是供奉在寺庙／骨灰殿里的神主牌。设计有很传统的，也有很新式的。

Zi Du An
自度庵

Nirvana Memorial Garden
富贵山庄

San Qing Gong
三清宫

 Bi Shan Ting
碧山亭

Ancestral tablet altar at home.

供奉在家里的神主牌。

Ancestral tablets on sale at shops selling ritual products.

神料用品商店内所售卖的神主牌。