I've never knocked a computer off the edge of a table because it was left with part of it extending beyond the edge. But leaving it like that does make increase

I've never knocked a computer off the edge of a table because it was left with part of it extending beyond the edge. But leaving it like that does make increase the risk of that happening. The same idea is true of picking it up by the edge; it increases stress on the hardware, which can cause damage. The fact that it hasn't happened to you just means it's isn't _sure_ to cause a problem.