Same for us, we have a strap that holds our in place when we travel. We forgot it once and when we stopped for fuel we discovered the screen of the TV was resting against the corner of the kitchen slide. Not a pretty site. We strapped it down and added it to the departure checklist!!
Just an FYI, we also shove a pillow into the microwave so the glass plate doesn't bounce around (I know it's off topic, apologies....)
2015 Sierra Denali 3500 Duramax\Dually
2011 Cyclone 3950 HD
2009 Harley Davidson Ultra Classic
2011 Can-Am Spyder RT-S Limited (DW's)
Usually a keg of beer....