I'd go the sand and water table. From my experience kids grow bored of activity tables that do the same thing ad can't be changed. If it's flexible I think it would get more/longer use. You wouldn't be limited to just sand and water either. You could pop in some coloured balls (too big for mouth) or different textured fabric (little kids love feeling the difference between velvets/wool/satins etc)... or rice play... where I worked toddlers LOVED pouring coloured or plain rice... if even goes through a water wheel.

I know a set activity table sounds easier and tidier but be prepared for her to get bored with that and then start roaming the house trying to get into cupboards etc.

Just my experience.