If you're using the tables 'all the way' then you're having a really bad day. Step 1 is memory items for pitch and thrust, which keeps you safe. Step 2 is to use the QRH to set accurate values from the table for speed which will allow you to hopefully establish if one of your 3 sources is reliable. If none are reliable then step 3 calls for table values for pitch and power. In the scenario you describe when reaching 5000ft you would maintain it with elevator and trim. The resultant power setting should correspond to the desired speed, just as you would expect: In level flight if you add a bit of power, trim to maintain level flight and you'll get faster.