Lazarus and the rich man's table Luke 16:21
What kind of table is this that the crumbs can fall from? I thought they were basically on the floor sitting on or around something spread out on which food was set.
During the first century A.D. and the time of Christ, wealthy Jews had adopted the Persian, Chaldean, Arabic and Roman customs of reclining on couches at a low table when holding special suppers or feasts.  The Romans had three couches on three sides of a square table.  The fourth side was left open for servants to assist in serving.  The guests would recline, resting on the left arm with the lower body stretched out.  This is how the woman could take her place behind Jesus to wash his feet (See Luke7:36-38)

With regard to the story of the rich man and Lazarus (Luke 16:19-21), the account describes how the rich man was clothed in purple.  He undoubtedly was wealthy enough to entertain lavishly and so his guests would no doubt recline on couches around a low table.  Crumbs will fall from a low tale to the floor.

The first link describes how Jews adopted the eating styles and customs of other nations and the second link gives an illustration of Jesus and his disciples reclining on couches round a low table.

https://www.bible-history.com/links.php?cat=39&amp;sub=477&amp;cat_name=Manners+%26+Customs&amp;subcat_name=Eating+Customs

https://www.google.co.uk/search?q=eating+furniture+Romans+Jews+first+century+AD&amp;tbm=isch&amp;source=iu&amp;ictx=1&amp;fir=JqpELiIlU-YSRM%253A%252CiVgZBhxN6zRmJM%252C_&amp;usg=__LdX-O-MLSJ6PrbqIEe55vX_0YHU%3D&amp;sa=X&amp;ved=0ahUKEwj0-tbG_ebbAhVNalAKHRm9AKgQ9QEIfDAI#imgrc=QjfZcLHrWGFzzM:

P.S. I did not downvote your question.