The Presidential Task Force on the Arts and the Humanities will recommend a variety of tax proposals to encourage private giving to the arts and the humanities.

At their last official meeting, held yesterday at the Library of Congress, the presidentially appointed group discussed a draft of the report that will be presented to President Reagan probably in mid-October. The draft, due for a reformulation before the president sees it, also suggests the establishment of presidential fellows in the arts and the humanities and a reactivated Federal Council on the Arts and the Humanities.

In addition, the task force gave a vote of approval to the National Endowment for the Arts and the National Endowment for the Humanities, and their system of awarding grants by panel review.

At an early point in the task force's three-month tenure, there was speculation about changing the government endowments into quasi-governmental agencies, like the Corporation for Public Broadcasting. That idea was later abandoned by the task force.

The tax proposals talked about yesterday, which the task force will recommend, include:

Eliminating the 50-percent ceiling on tax deductions taken for gifts to public charities. The annual amount now deductible may not exceed 50 percent of income.

Raising the 20-percent limitation on gifts to private foundations to 50 percent.

Raising the 30-percent limitation on gifts of appreciated property to 50 percent.

Extending the charitable contribution carry-over period from five to 15 years. When charitable gifts exceed the set annually deductible percentages, the excess may be deducted in each of succeeding taxable years of contribution.

The task force, taking care to avoid overt criticism of Reagan's new tax laws, has indicated that the new tax laws could inadvertently deter private contributions to the arts. Hence, these proposals.

Hanna Gray, a chairman, and the group have also talked about reconstituting Federal Council on the Arts and the Humanities. "It's not starting a new agency but it could help to bring together public and private agencies," said Gray.

The council consists of chairmen of various institutions including the NEA, the NEH, the National Gallery of Art, the departments of state, commerce, education, interior, and transportation, and the Smithsonian. The task force wants private citizens included on the council and wants the council to meet regularly.