Starting with the assumption that you are not wanting to turn these events into productions one way to do this is to put lights into the corners, aim them upwards at the ceiling, and just let it bounce and spill around the room. This is a variant on the 'naked bulb' method employed by event and commercial photographers to fill a room with light. LED lights can be powerful when they are the high output version, most of the panel types are not that intense a light source. Do check for the specified outputs of the lights for comparison. More important than the type of bulb you buy is being able to match the colour temperature of the existing light sources. If mixed bulb types are present in the room replace the ones that don't match unless you want to use the different colours for artistic purposes. It is also possible to change out existing low wattage bulbs for ones with more output. Halogen lights usually are not used for general indoor lighting as they produce a LOT of heat.