Can these tree trunks be used for a small table?
Yes, you can - Absolutely! As @Henry Taylor suggests: it would be a good idea to kill off parasites, termites, etc.


If you cut or sand-down the ends, be sure they are level so the top of your table is not at an angle. 
You can choose to coat the top with a urethane coating, or just lay a piece of glass, plexiglass, or polycarbonate over the top so you have a smooth top.
If you wish, they also make great planters. You can carve or gouge a hole in the top; drill a hole for water to drain from, and either put a pot in it with flowers or just fill it with dirt and directly plant something in it.
Also, if you plan to use it for a bedside, or end-table next to a couch or bench, you can use something like a brass, or copper tube and wire-up a built-in lamp.


Best of luck @rbhat!