Is the word aproveitar the same in Brazilian and European Portuguese?

No.

While the dictionary definition, spelling, and grammar of "aproveitar" are identical in both varieties, there is a difference in typical usage. In Brazilian Portuguese, "aproveitar" is frequently used as a common way to wish someone enjoyment in social contexts (e.g., "Enjoy the party!"). In Continental Portuguese, while "aproveitar" is used to mean "making the most of" an opportunity or resource, speakers are more likely to use "divertir-se" (to have fun) for social enjoyment, and they almost exclusively use the set phrase "bom proveito" rather than the verb "aproveitar" when referring to meals.

Brazilian Portuguese Examples

1. Aproveite a festa! (Enjoy the party!)
2. Vamos aproveitar o dia de sol. (Let's take advantage of the sunny day.)
3. Você precisa aproveitar as oportunidades que surgem. (You need to take advantage of the opportunities that arise.)
4. Aproveite o seu almoço! (Enjoy your lunch!)
5. Eu vou aproveitar as minhas férias para descansar. (I am going to make the most of my vacation to rest.)

Portuguese (Portugal) Examples

1. Diverte-te na festa! (Have fun at the party!)
2. Vamos aproveitar o dia de sol. (Let's take advantage of the sunny day.)
3. Deves aproveitar as oportunidades que surgem. (You should take advantage of the opportunities that arise.)
4. Bom proveito! (Enjoy your meal!)
5. Eu vou aproveitar as minhas férias para descansar. (I am going to make the most of my holidays to rest.)