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

Yes

The word "lenta" is identical in meaning, spelling, and grammatical function in both Brazilian and Continental Portuguese. The only difference is the pronunciation (accent). In Brazilian Portuguese, the vowels tend to be more open and the "e" is more clearly articulated. In Continental Portuguese, the vowels are often more closed or reduced, which can make the word sound more clipped or "tighter" to a Brazilian ear.

Brazilian Portuguese Examples

1. A internet está muito lenta hoje. (The internet is very slow today.)
2. Ela tem uma caminhada lenta. (She has a slow walk.)
3. Essa música é muito lenta e relaxante. (This music is very slow and relaxing.)
4. A resposta dele foi bem lenta. (His response was quite slow.)
5. A viagem foi muito lenta por causa do trânsito. (The trip was very slow because of the traffic.)

Continental Portuguese Examples

1. A ligação está muito lenta hoje. (The connection is very slow today.)
2. Ela tem um andar lento. (She has a slow walk.)
3. Esta música é muito lenta e relaxante. (This music is very slow and relaxing.)
4. A resposta dele foi lenta. (His response was slow.)
5. A viagem foi muito demorada. (The trip was very slow/long.)