Even now (opera 37) or then I'm unable to reproduce this issue on a Chinese Tablet running Android 4.4 (I think 4.4.4 is still in first dev tier). At first run (session) Opera browser may have more than 300MB in cached processes on heavy load and after recalculation up to 270MB for 9 open tabs (max cache when Opera Turbo is on). Running low Opera consume 100MB cached and 10 MB from real RAM (as per 1GB RAM) so Opera browser may work properly on devices with 400MB free RAM + @300MB fee USB storage and minimal requirement must be 150MB free RAM (at least 20MB for Google processes + other stuff).
Opera for Android